Report of the Committee on
Richard L. Koehler, American Fire & Electric Industries, Inc.
(Alt. to W. A. Eckholm)
Edward D. Leedy, Industrial Risk Insurers
(Alt. to S. A. Chines)
Ea~t.ames McCarty, Reynolds Electrical & Engr. Co~, Inc.
to P. E. Phillips)
W]lllam H. Mclntyre, Johnson and Higgins
'
(Alt. toJ. A. Sileo)"
Peter L Rullo, American Risk Management Corp.
(Alt. to I. Nibur)
James Robert Ryan, Kemper Group
(Alt. to S. L. Rogers)
1
HowardJ. Spice, Underwriters' Laboratories of Canada
(Alt. to R.J. Wright)
Mark A. Sweval, Great Lakes Chemical Corp.
Halogenated Fire Extinguishing Systems
Thomas J. Wrsockl, Chairman
Guardian Services, Inc.
S. L. Rogers, Secretary
Kemper Insurance Cos.
(Rep. The Alliance of American Insurers)
William M. Cmmy, Underwriters Laboratories, Inc.
Salvatore A. Chines, Industrial Risk Insurers
William A. Eekholm~ Fike Fire Suppression Systems
Rep. Fire Suppression Systems Assoc.
James P. H,eberh Universal Fire Equipment Co.
Rep. Nat 1Assoc. of Fire Equipment Distributors, Inc.
John R. Jolmson, GTE Service Corp.
David H. Kay, US Dept. of the Navy
Dennis C. Kennedy, RolfJensen & Assoc., Inc.
Robert C. Merrith Factory Mutual Research Corp.
Daniel W. Moore, E.I. duPont deNemours & Co., Inc.
{~tth~lDW.Mossel, ICI Americas, Inc.
• Neargarth, Ansul Fire Protection
Rep. Fire Equipment Manufacturers' Assoc., Inc.
Ivan M. Nibur, American Risk Management Corp.
Lyle R. Perkins, Florida Power Corp.
Rep. Electric Light Power Group/Edison Electric Institute
Ken C. Phillips, EG&G Idaho, Inc.
Rep. NFPA Industrial Fire Protection Section
Patrick E. Phillips, US Dept. of Energy
John A. Sileo,Johnson & Higgins
Steven M. Stolerow, Schirmer Engineering Corp. "
Robert E. Tapseoth University of New Mexico
Gary M. Taylor, Taylor/Wagner, Inc.
D. R. Todd, Levitt-Safety Ltd.
Rep. Fire Equipment Manufacturers'Institute of Canada
I ~ u s Wahle, US Coast Guard
"
Fred K. Walker, H Q U S Air Force/LEEDE
Stephen B. Waters, Fireline Corp.
Rep. Halon.Research Institute
R.J. Wright, Underwriters Labs of Canada
(Alt. to S. B. Waters)
Stuart D. Woodman, Chubb Fire Security
(Alt. D. Todd)
Nonvoting
George A. Krabbe, Automatic Suppression Systems, Inc.
Pep. T / C Elec. Computer Sys.
Y. Speetor, SpectronixLtd
H. V. ~0(illlamson, Roscoe, IL
Rep. T / C Carbon Dioxide
StaffLiaison: Mark T. Conroy
This list represents the membership at the time _the Committee
was balloted on the text of this ediuon. Since that dme changes
in the membership may have occurred.
The Report of the Committee on Halogenated Fire Extinguishing
Systems is presented for adoption.
This Report wasprepared by the Technical Committee on
Halogenated Fire Extinguishing Systems and proposes for adoption a
complete revision to NFPA 12A., Standard for Halon 1301 Fire
Extinguishing Systems. NFPA 12A is published in Volume I of the
1991 National Fire Codes and in separate pamphlet form.
This Report has been submitted to letter ballot of the Technical
Committee on Halogenated Fire Extinguishing Systems which
consists of 26 voting members; of whom 19 voted affirmatively, 1
negatively (Mr. Wahle), and 6 ballots were not returned (Messrs.
Johnson, Neargarth, Stolerow, Tapscott, Todd and Wright).
Alternates
Charles B. Barnett, ASCOA Fire Systems
(Alt. to E. D. Ne~igarth)
Kerry M. Bell, Underwriters Laboratories, Inc.
(Alt. to W. M. Carey)
. . . . .
Robert L. Darwin, Dept. of the r~avy- tire rroL uiv.
(AIt. to D. H. Kay)
Alfred P. Dougherty, E.I. duPont deNemours & Co., Inc.
(Alt to D. W. Moore)
David R. Fiedler, RolfJ,ensen & Assoc., Inc.
(Alt. to D. C. Kenneay)
Sqilljara D. Hard, Hard Suppression Systems (Alt. toJ. P. Hebert)
Mr. Wahle voted negatively stating:
=4-2.1 (1-9.4.5.1) cites the Code of Federal Regulations, 49 CFR
173.34(e) (10), as the source for permitting a visual (external)
inspection of cylinders in lieu of a periodic hydro test. This is a
misinterpretation of the CFR, since according to DOT, this applies
only to "flourinated hydrocarbons and mixtures thereof." Since
nitrogen is not a flourinated hydrocarbon, cylinders charged with
Halon 1501 and nitrogen do not qualify for this exemption, and must
be hydro tested every five years."
I
563
'
NFPA 12A ~
(Log # 91)
12A- 7 - (1-7.4.1.3 E.)): Accept in Principle
SUBM1TrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Revise the following:
"E. Enclosure Integrity Test. All total flooding systems shall have all
significant airleaks that would affect the enclosures ability to hold
halon located and sealed. The enclosure integrity shall be examined
and tested. Examination, shall be with a door fan and smoke pencil
or by any other means capable of accurately locating leaks. The
enclosure shall be tested to verify its ability to hold a Halon 1301
concentration for the specified period of time. The tes't shall follow
the Enclosure Integrity Procedure in Appendix B of NFPA 12A and
such other procedures as required by the AHJ."
SUBSTANTIATION: The existing section discusses sealing up leaks
so the enclosure is tight enough to hold halon but doesn't say how to
determine ff it is tight enough. It implies an examination is ok and
presumably the "test" is the room integrity procedure in Appendix",B
but it doesn't say so. Could this be the discharge test?
Stating the enclosure can be accepted with a leak examination is
dangerous, and unnecessa.7 . Unless someone, can evaluate these.
rooms vasually on what basts are they bemg approved? Rewritten,
also, for clarity.
COMMITrE~ACTION: Accept in Principle. (See proposal 12A122, paragraph 4-7.2.2).
.
.
.
In existing text change ~or" to and after examined.
C O M M r r r E E STATEMENT: Clarification.
(Log # 20)
12A- 1 - (1-5.3.2): Accept in Principle
SUBMITI'ER: William Eckholm, FSSA
RECOMMENDATION: Add to listing:
"(g) Telecommunications Facilities.
SUBSTANTIATION: Protection of telecommunication facilities is a
common application of Halon 1301 systems.
COMMITTEE ACTION: Accept in Principle.
Add as (b) Telecommunications (see proposal 12A-122, paragraph
1-4.2.2).
C O M M I ' r I ' ~ STATEMENT: Accepted recommendation and relocated.
(Log # 21)
12A- 2 - (1-5.4): Accept
'
SUBMITrER: William Eckholm, FSSA
RECOMMENDATION: Retain the first three sentences. Delete
remainder of paragraph, starting with "Water supplies..."
SUBSTANTIATION: The reference to sprinkler systems is inappropriam in the standard for Halon 1301systems. No such cross
reference covering the advantages of Halon systems is contained in
the standard for Sprinkler Systems (NFPA 13).
COMMITTEE ACTION: Accept. (See proposal 12#_-122, paragraph
1-4.2.7).
(Log # 24)
12A-3- (1-7.4.1.1): Reject
SUBMITI'EI~a William Eckholm, FSSA
RECOMMENDATION: In the first and second sentences, change
"10 minutes" to "1 minute."
SUBSTANTIATION: The ten minute holding period for a pneumatic test is considered unnecessary. The halon cylinder, which
forms a part of the same delivery system, is only required to pass a
one minute test per DOT requirements.
COMMITrEEAGTION: Reject. (See proposal 12A-122, paragraph
4-7.2.1(1)).
COMMITI'EE STATEMENT: Insufficient rationale or data
submitted to reduce the requirement.
I
A92 TCR
(Log # 92)
12A- 8 - (1-7.4.1.3 E): Accept in Principle
SUBMITTER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Revise the following:
"E. Enclosure Integrity Test. All total flooding systems shall have all
significant airleaks, that would affect the enclosures ability to hold
halon, located and sealed.
An examination or test shall be successfully completed to determine
whether the room has been sutficiendy well sealed to hold a halon
concentration for the specified time.
1. If examined, a detailed inspection of all possible leakage sites in
the enclosure envelope must be completed using a door fan along
with'an air current tester or such other means o f accurately pinpointing leaks to check allpossible leakage sites.
The AJH shall decide on the basis of this examination whether the
enclosure is sufficiently well sealed. Even though the examination
may be used for original acceptance the Enclosure Integrity
Procedure should be completed to enable future re-acceptance.
2. If tested, the Enclosure Integrity Procedure per NFPA 12A,
Appendix B and such other procedure(s) as may be required by the
AHJ shall be successfully completed."
SUBSTANTIATION: The emsting section discusses sealing up leaks
so the enclosure is tight enough.to bold halon but doesn't say how to
determine if it is tight enough. It implies an examination is ok and
presumably the "test" is the room integrity procedure in Appendix B
but it doesn't say so. Could this be the discharge test? If the room
can be accepted based on an examination and nothing else, more
details of the examination must be given plus the AHJ must be made
aware that he must determine whether or not the room integrity is
acceptable based on this examination. Many rooms have been sealed
using a door fan and smoke gun to locate leaks and have passed
discharge tests so the method works. The leak examination must be
thorough and be accompanied by a means of qualifying suspect leak
sites. Lastly, the existing section does not say the room can be
accepted without a discharge test which is clearly not our intention.
We want the enclosure integrity procedure to replace discharge tests
where possible.
The proposed wording allows for acceptance based as an examination or the enclosure integrity procedure or the discharge test or any
other test. It also accomodates the former tests to ensure discharge
test passage.
In the past, examinations have been allowed as the only test of
enclosure integrity without any guidelines and without anyone being
aware that the enclosure integrity question just got swept under the
(Log # 25)
12A-4- (1-7.4.1.3 C.3): Accept
SUBMITTER: William Eckholm, FSSA
RECOMMENDATION: Revise to read:
"Power shall be supplied to the control unit from a separate
dedicated source which will not be shut down on system operation."
SUBSTANTIATION: Clarification of intent. It is necessary that
alarms, etc. remain powered after system activation.
COMMITTEE ACTION: Accept. (See proposal 12A-122, paragraph
4-7.2.3(c)).
(Log # 98)
12A- 5 - (1-7.4.1.3 D.): Accept
SUBMITTER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Remove the words "or Predischarge Test"
from 1-7.4.1.3 D and the word "(predischarge)" from 1-7.4.1.3 D.1.
Change the word ~predischarge~"to ~funcuonal test"
SUBSTANTIATION: The use of the word ?redischarge supposes a
discharge test will be performed. This is mtsleading because it is
expected that very few will be discharged in future.
COMMITI'EEACTION: Accept. (See proposal 12A-122, paragraph
4-7.2.4).
(Log # 2 6 )
12A- 6 - (1-7.4.1.3 E.): Reject
SUBMITTER: William Eckholm, FSSA
RECOMMENDATION: Revise to read:
"The currently preferred method of testing is using a blower door
fan unit and smoke pencil."
SUBSTANTIATION: Clarification. The first sentence calls for either
examination or test. Adding the words %f testing" clarifies that the
door-fa'n method applies only to test (not examination).
COMMITTEE ACTION: Reject. (See proposal 12A-122, paragraph
4-7.2.2).
COMMITTEE STATEMENT: The proposed editorial clarification .
does not add clarity.
c r u ( ~ E I T E E ACTION: Accept in Principle. (See proposal 12A122, paragraph 4-7.2.2).
COMMITTEE STATEMENT: Refer to action on Proposal 12A-7
(Log#91).
564
!
--.
f
NFPA 1 2 A - A92 TCR
(Log # sol
(tog # 27)
12A- 12 - (1-10.1.1 (a)): Accept in Principle
SuBMrvr~
William Eckholm, FSSA
RECOMMENDATION: Revise first.sentence to read:
"Black or galvanized pipe shall be either ASTM A-53 or ASTM A106."
SUBSTANTIATION: Present wording does not recognize furnace
welded pipe ASTM A-53 Class F, which is included in A-l-10.1.
It is not considered necessary to call out fabrication method, or
grade in this paragraph. Definition of the applicable ASTM
specification ts sufficient.
.
COMMITrt2EACTION: Accept in Principle.
Delete the first two sentences of 1-10.1.1 (a) and all of (b). (See
proposal 12A-122, paragraph 2-2.1.1).
COMMITTEE STATEMENT: Remaining text provides the minimum
requirement. Appendix material added during the 1989 revision
provides sufficient guidar/ce for selection of materials.'
12A.-9 - (I-7.4.1.3F): Accept in Part
S U B ~ :
William Eckholm, FSSA
RECOMMENDATION:
Delete the firstsentence.
Revise se'cond sentence to read:
"A test,such as a "puff test"with nitrogen shallbe performed to
check for continuous and obstruction frcc piping."
S U B S T A N T I A T I O N : Use of compressed air or carbon dioxidc can
introduce moisture into cylinders,piping and ancillarydcviccs. Use
of carbon dioxide may subject piping, etc. to pressure beyond dcsigu
limits due to the high vapor pressure of carbdn dioxide. With the revised wording, the p.resent first sentence is unncessary.
I COMMITI'EE ACTION: Accept m Part.
Revise to read as follows:
"A puff test with nitrogen shall be performed to check for continuous piping."
.
COMMaI lv:~. STATEMENT: (See proposal 12A-122, paragraph, 47.2.1(m)).
(Log # 31)
12A- 13 - (1-10.2.1): Accept in Principle
SUBMH'TER: William Eckholm, FSSA
RECOMMENDATION: Add "grooved" to the list of suitable joints
and fittings.
SUBSTANTIATION: Grooved fittings are listed for use on Halon
1301 systems. Grooved fittings are included in A-I.10.1.1.
COMMYrTEE ACTION: Accept in Principle.
Replace 1-10.2.1 with:
~Pipingjoints, of other than the screwed or flanged type, shall be
listed or approved for this application." (See proposal 12A-122,
paragraph 9-2.2).
COMMrlq'EE STATEMENT: The committee concurs with the
' submitter but recognized there may be others.
(LOg # 28)
12A- 10 - (I-8.6.1(New)): Accept in Principle
S U B M I T T E R : William Eckholm, FSSA
RECOMMENDATION:
Add a new subparagraph as follows:
"1-8.6.1 Inhibit (isolation)Switch. Each halon system used with
automatic detection shallbe provided with an inhibit (isolation)
switch,for each hazard area.
The function of this switch,when activated,is to inhibitor prevent
discharge of the halon releasingcircuit,through the automatic
detection system. Manual electricactivationof the halon system shall
bypass the inhibitswitch circuit. Activation of the inhibitswitch shall
actuate a trouble signal (both visualand audible) on the control
panel. The inhibitswitch may be located within the control panel, or
as a remote located key lock switch. The inhibitswi{ch shallbe
properly identifiedas to itsfunction."
S U B S T A N T I A T I O N : Provision of such a switch willallow isolationof
the detection system during maintenance operations. Unintentional
system activationsometimes occurs during maintenance of air
conditioning equipment, ctc.
Reducing inadvertent actuations is a major issue in the effortto
reduce halon emissions (Ozone layer Question,)
COMMII-It=E A C T I O N : Acce~t in Principle.
Add the following:
A-2-1.6 Equipment qockouC or."servicedisconnects"
can be instrumental in preventing falsedischarges when the Halon
1301 system is being tes(cd or serdced. In addition, servicingof air
conditioning systems with the release of refrigerantaerosols,
soldering, or turning electricplenum heaters on for the firsttime
after a long period of idleness may tripthe Halon 1301 system.
Written procedures should be establishedfor taking the Halon 1301
S~Sstemout of service.
ce proposal 12A-122, paragraph, A-2-1.6).
C O M M I T T E E S T A T E M E N T : The committee feltthere was a nccd
for guidance in thisarea. Many manufacturer's supply thisdevice
presently.
•
o
,
•
(Log # 99)
1P.A- 14- (1-10.5.4): Reject
SUBMITTER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Add the following sentence:
"Discharge nozzle orifice diameters shall not be altered through
field or shop modifications."
SUBSTANTIATION: To stricdy prohibit the practice of redrilling
orifices following receipt of nozzles from the manufacturer.
COMMITTEE ACTION: RejecL (See proposal 12A-122, paragraph
2-2.5.4).
COMMITrEE STATEMENT: This subject is adequately covered by
1-7.4.1.3 and 1-10.5.4.
(Log # 2)
12A- 15 - (1-10.6.1): Accept in Principle
.
SUBMITTER: Donald Applegate, Pem All Fire Extinguisher Corp.
RECOMMENDATION: Revise the following:
"1-10.6.1 As part of the design procedure, system flow calculations shall be perfo/med using the current listed calculation method
(Standard for Halongenated Agent Extinguishing System Units, 058).
Compliance to this requirement shall be confirmed by including a
statement on the hydraulic flow calculation computer printout noting
the manufacturer's version of the flow calculation program and
compliance with the latest 058 standard."
SUBSTANTIATION: The aboveproposed wording of Paragraph 110.6.1 is intended to prevent the-design of Halon 1301 systems with
hydraulic flow calculation programs that were used prior to the
current standard of design (Standard for Halogenated Agent
Extinguishing System Units, 058). This current standard (058) was
established as a result of discovering that predicted flows of Halon
1301 in extremely unbalanced piping networks did not match actual
flows achieved in discharge tests.Since the institution of the current standard (058), all manufactur-"
ers of
H a l o n . 1301. Ssystqstems.e q ui p ment have. altered and ad'uste'dtl their.
versions of thetr hydrauhc flow calculauon programs to comply with
the more stringent requirements of the standard. However, hydraulic
flow calculation programs that were in existance prior to the current
058 standard are still being used by some manufacturer's distributors.
In fact, some manufacturers have not yet released their 058 version to
their distribution.
Authorities having jurisdiction receive a computergenerated
hydraulic flow calculation for their stamp of approval but have no way
of knowing whether or not the flow program used is in compliance
with the current 058 standard.
•
C O ~
ACTION: Accept in Principle.
(Log # 29)
12A- 11 - (1-9.4.2.1 (New)): Reject
SUBMITTER: William Eckholm, FSSA
RECOMMENDATION: Add a new subparagraph as follows:
"1-9.4.2.1 The cylinder markings shall include:
(a) Contents product name as tt appears on the manufacturer's
Material Safety Data Sheet (MSDS).
(b) HazardMaterial Identification in accordance with the
Hazardous Materials Identification Sptem (HMIS).
(c) Identification of the hazard(s) revolved, in accordance with the
Material Safety Data Sheet (MSDS).
(d) Manufacturer's name and address as shown on the Material
Safety Data Sheet.
The information may be incorporated in the standard cylinder
nameplate, or may be on a supplementary tag or label:
NOTE: In Canada see Workplace Hazardous Materials Identification
System (WHMIS)."
SUBSTANTIATION:. Recommended wording will warn of hazards by
means of an accepted, regulated system.
COMMITTEE ACTION: Reject. (See proposal 12A-122, paragraph
2-1.4.2).
COMMITTEE STATEMENT: Beyond the scope of standard. "
565
NFPA 12A
Add the following to 1-7.2.4:
"The manufacturer s version of the flow calculation program shall "
be identified on the computer calculation print out. Only the
currently listed calculation method shall be used. (See proposal 12.4.122, paragraph 3-1.2.4).
COMMITTEE STATEMENT: The committee agreed with the
concept but made the requirement generic to be added to a different
paragraph.
(Log# 1)
12A- 16 - (1-10.6.1, 1-10.6.6, 1.10.6.7, A-1-10.6.6 and A-1-10.6.6(b)):
: Hal Sanders, Hal R. Sanders & Associates, Inc.
RECOMMENDATION: Revise paragraph 1-10.6.1 to read:
"System flow calculations shall be basedon the methods given in this
section."
Reviseparagraph 1-10.6.6 by adding the following:
"In addition to the pipeline pressure drop, system calculations shall
include velocity pressure changes at flow splits and pipe size changes
based on the following equation:
Velocity head = 3.63 x
pD 4
Where: Q i s the flow rate in Ibs./sec.
p i s t h e density in Ibs./cu ft,
D is the diameter in inches
Revise 1-10.6.7 by adding the following sentence"Nozzle discharge calcul-afions shall be based on manufacturer's
published nozzle spedficadons to include specific flow rate or
percent of maximum theoretical discharge from an open pipe in
accordance with the listing of the nozzle.
Add second paragraph to opening paragraph A-1-10.6.5 and A-l10.6.6(b):
"Flow calculations below are based on pipeline pressure losses and
do not include velocity pressure changes at flow splits o r p i p e size
changes. Also, terminal pressures are static pressures a n d d o not
include the effects of velocity pressure. More accurate analysis of
system losses for design purposes should incude the use of velocity
pressure."
SUBSTANTIATION: 1-10.6.1 -The last phrase of the existing text " . .
• or any.other method approved or Listed by a testing laboratory,"
permits the likely possibility of numerous methods of calculation,
which are acceptable to testing laboratories. The definition of
"Listed" in Paragraph 1-4 and "Official NFPA Definitions" refers to
equipment or materials, neither of which can be construed as a
"method of calculation." Also, the use of "a testing laboratory" in this
case seems to permit any testing laboratory, regardless of quaiifications to determine the adequacy of calculations.
If calculations are left exclusively to manufacturers of devices, who
must have a listed computer calculation program, which somehow
corroborates test results for a given system, regardless of its calculation method, NFPA and the engineering community have been
abandoned as far as "standards for design" are concerned. It would
appear to me that "listing" or "approval" should be limited to preengineered systems.
1-10.6.6 The use of velocity pressures for calculating terminal
pressure at nozzles is recognized in appendix par. A-1-10.6.7,
however, it is not specifiedfor system flow calculations. Use of
velocity pressure change flow splits and pipe size changes can result
in more accurate calculations, particularly for larger systems.
1-10.6.7 Basic nozzle design is not complicated and varies very little
between manufacturers, however, present methods of secrecy
through listing of nozzle discharge data or codes and calculation
programs, limiting the use of a single manufacturer's nozzles per
system creates, purchasing and design problems when modification
or expansion of the system occurs. If other manufacturer's distributors are desired for such work, the system must be completely
redesigned using another manufacturer's nozzles, according to the
present.wordin[~, essentially eliminating competitive bids for
renovauon worx.
A-1-10.6.6 a n d A-1-10.6.6(b) - Present sample calculations provide a
means for system check, but are unnecessarily inaccurate for system
design. Future examples should include complete analysis in order
for the user to gain a b e t t e r understanding of two-phase flow.
COMMn'I'EE AGTION: Reject.
C O M M r F I ' ~ STATEMENT: Submitter refers to the 1987 edition.
The subject is adequately covered in standard.
A92 TCR
RECOMMENDATION: Add 1-11.1.10:
"1-11.1.10 At least every two years the Enclosure Integrity Test from
section 1-7.4.1.3 E shall be repeated. Discharge tests shall not be
repeated. The Enclosure I n t e ~ ' t y. Procedure
. . . can be used to reaccept the room even though it failed this test originally as long as the
discharge test or..such other procedure, required b~ the AHJ was
passed upon ongtnal acce~tance.. It ts parucuiarly, mmportant, to repeat
all steps of the Enclosure Integrity Procedure since height, volume,
leakage area, static pressure and such can easily change.
If an examination alone was used for original acceptance, the same
• procedure a n d / o r the Enclosure Integrity Procedure may be used for
future re-acceptance."
SUBSTANTIATION: The section 1-11.1 dealing with inspection and
tests does not currently address the most likely cause of a system not
performing as designed in the event of a discharge. Most discharge
failures are caused by a lack of room integrity. After inltial.acceptance, most halon protected enclosures experience modifications and
wear which compromise their integrity, often by a lot. Reapplying the
inexpensive, fast and non-disruptive Enclosure Integrity Procedure,
for.the first time allows one of the most important checks to be made.
COMMITTEE ACTION: Accept in Principle.
Add 1-11.1.10 as follows:
1-11.1.10 At least every six months the halon protected enclosure
shall be thoroughly inspected to determine if penetrations or other
changes have occurred that could adversel), affect halon leakage.
Where the inspection indicates that conditions that could result in
inability to maintain the halon concentration, they shall be corrected.
If uncertainty still exists, the enclosure shall be re-tested for integrity.
(See proposal 12A-122, paragraph 4-4).
COMMITTEE STATEMENT: The committee felt a need for
periodic inspection but a requirement for periodic testing might
create an unncessary burden.
J
12A- 18- (2-2.2.4): Accept
SUBMITTER: Technical Committee on Halogenated Fire Extinshing Systems
COMMENDATION: Add:
"including in-room air conditioning units." after "Forced-air
ventilation systems"
SUBSTANTIATION: Clarification.
COMMrIWEEACTION: Accept. (See proposal 12A-122, paragraph
3-3.4).
~l~
(Log # 100)
12A- 19 - (Table 2-5.2): Reject
SUBMITYER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Add the following to the foomotes section of
the referenced table:
Following (4) added the following equation:
C= I00
V + 1 RAWMARKS
WS
(5) V [Volume fits) ] -Maximum net volume of enclosure•
V = 100-C WS
RAW MARKS
C
SUBSTANTIATION: The addition of these two equations provide a
ready means of calculating a single unknown value, either C o t V,
when the two remaining quantiues are known. These values may not
be readily apparent, particularly if system or enclosure changes have
taken place during construction. These values are generally required
to utilize published enclosure integrity procedure software.
COMMITTEE ACTION: Reject.
The proposal is just a rearrangement of the existing equation.
(Log # 76)
12.4.- 90 - (2-6.2, B-2.6.2.1 and B-2.6.2.5): Accept in Principle
SLrBMrl'rER: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Revise Section 2.6.2 Suspended Ceiling
Neutralization Method.
Add in 13-2.6.2.1 as last sentence:
"This technique has not been tested under controlled conditions
and its estimates should be used with caution.
No error estimates or limiting conditions have been identified."
Add in 13-2.6.2.5 as last sentence:
"Note that smoke is a qualitative technique that gives no estimate of
the magnitude of the j~ressure being neutralized and there may be
large errors if. the iniual, pressure is very small or the smoke is not
properly apphed."
(Log # 90)
12A- 17 - (1-11.1.10 (New)): Accept in Principle
SUBMITTER: Colin Genge, Sheltair Scientific, Ltd.
566
NFPA i2ASUBSTANTIATION: We have not found any literature describing
controlled experiments, limits, or errors of this technique. Our
experiments have shown that there are pressure differences of 0.001
'~'c across some ceilings and that an attempt to use ceiling neutralizadon with smoke tracers could produce large errors.
C O M M r r r E E ACTION: Accept in Principle.
C O M M r r r E E STATEMENT: Refer to acuon on Propos~ 12A-97
(Log #55).
J
(Log # 85)
12A. 21 - (2-11 (New)): Accept in Principle
SUBMrrrER: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Add new section on Engineering Judgment
(2.117)
"2.11 EnglneeringJudgrnent. In som~ cases the door fan results
should be overruled as too pessimistic. For instance, a room with
Pthainted concrete walls, a concrete slab floor, and no penetrations in
e slab or the lower wall can be guaranteed to hold halon despite
large leaks in the ceiling or overhead ductwork. 'The use of visual
inspection to prove that lower leaks do not exist is an appropriate
method to overrule the results of a door fan test. This inspection
should include a standard door fan test and the use of smoke tracers
to search for leaks."
SUBSTANTIATION: The limitations of the door fan test should be
recognized and the cases in which it is inappropriate should be
established.
A92 TCR
retained in the room. Upon installation of this system, ali doors were
equipped with automatic closures, gaskets and floor seals; all cables
and conduits leading out of the room were sealed (including those
" above the ceiling and below raised floors); and all leaks or cracks'
were sealed. The room was door fan testedper NFPA 12A, Appendix
B, to assure itwas properly sealed to retain the Halon. For the safety
of the occupants and eqmpment in this room:
• (a) Doors must not be blocked open
(b) All gaskets and seals must be maintained in good operating
condition
(c) Any new cables or conduits leading in or out of the room
must be caulked and sealed
(d) The room must be retested and certified annually or
whenever alteration are made to the walls, floor or ceiling.
DATE OF LAST TEST
TESTING COMPANY ,
LOCATION OF TEST REPORT"
SUBSTANTIATION: Minimum standards for an enclosure notice
would ensure that occupants understood the requirement for
maintaining sealing.
COMMITTEE ACTION: Reject.
Adequately covered in the standard by existing text.
/
(Log # 5)
12A- 24 - (Chapter 3): Accept in Principle SUBM1TrER: Thomas Wysocki, Frankfort, IL
RECOMMENDATION: Delete Chapter 3 and all references to local
a lication.
~)I~lete 1-5.5.3
Delete 1-10.5.3
Delete A-5-1
Delete A-3-3
SUBSTANTIATION: Dele.tin~ the references to local application
Ha]on 1301 systems is appropriate since:
1. There is no public interest in these sections of the standhrd as
evidenced by lack of previous public comment.on them.
5. To date there have been no Halon 1301 systems listed for local
application. In view of the desire to make "best use" of Ha]on 1301,
non-essential application should be eliminated. Since there have
been no local application Ha]on 1301 systems listed, it should be
apparent that local application Halon 1301 is a non-essential use.
t r u e r agents, such as CO o, foam, dry chemical and water, continue
to fill the need for local al3plication agents.
C O M M r r r E E ACTION: Accept in Principle.
The recommended changes are accepted.
Additionally delete 1-5.5.1 and movel-5.5.2 to definitions.
In scope change first sentence to read:
"This standardcontains minimum requirements for total flooding
Ha]on 1301, Fire Extinguishing Systems."
COMMITTEE STATEMENT: The committee felt the additional
changes were necessary to complete the submitter's intent.
C O M M r r r E E ACTION: Accept in Principle.
Add a new section B-1.2.2.5 as follows:
,"Igl.9.9.5 Technical Judgment. Enclosures with large overhead
leaks, but no significant leaks in the floor slab and wails will yield
unrealistically short retention time predictions. Experience has
shown enclosures of this type may l~e capable of retaining' ha]on for
prolonged periods. However, in such cases the Authority Having
Jurisdiction may waive the quantitative results in favor of a detailed
witnessed leak inspection o f all floors and walls with a door fan and
smoke pencil.
(See proposal 12A-122, paragraph B-1.2~2.5).
C O M M r r r E E STATEMENT: Editorial clarification and relocation.
-
( L o g # 86)
12A- 22 - (2-12 (New)): Accept in Principle
SUBMrIWER: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Add new section on test report (2.127)
"2.12 Test Report. Upon completion of a door fan test a written test
report shall be prepared for the AHJ and made part of the permanent record. The test report shall include:
(a) Date, time, and location of test
(b) Names of witnesses to the test
(c) Room dimensions and volume
(d) All data generated during test, including computer printouts
(e) Descripuons of any special techniques utilized by test
technician (i.e., use of optional ceiling neutralization, and temporary
sealing of suspended ceiling)
(f)
In case of engineering judgment, a full explanation and
documentation of the j u d g m e n t
(g) Copy of current calibration certificate of test equipment
(h) Name and affiliation of testing technician, and signature."
SUBSTANTIATION: Minimum standards for test report contents
would ensure that all vital data is available for review.
COMMrrTEE ACTION: Accept in Principle.
Add the recommended text o f the submitter as 13-2.9 with the'
following change: Change "engineering" to "technical" and
Insert: "(g) test equipment make, model, and serial number"
Redesignate exisung (g) and (h) to (h) and (i) accordingly.
COMMITTEE STATEMENT: The committee felt the additional
material was also necessary for the test report.
12A- 25 - (A-1-6.1.2 (g)): Reject
(Log # 22)
SUBMrrrER: William Eckholm, FSSA
RECOMMENDATION: Revise last sentence to read:
"Personnel such as in-plant fire brigades, or local fire departments,
are considered to meet these criteria."
SUBSTANTIATION: Clarification. Present wording does not define
trained versonnel.
COMMITrEEACTION: Reject.
" •
Present wording specifically states criteria without stating those that
may qualify.
COMM1TrEE $ T A T E M ~ .
(See proposal 12A-122, paragraph A-46).
(Log # 69)
12A- 26 - (A-1-7.4 C.1 and C.2): Accept in Principle
SLrBMITrER: George A. Shia, Allied-Signal, Inc.
RECOMMENDATION: Replace section A-1-7,4 paragraph C, subparagraphs 1 and 2 with the following: '
"C. The following procedure should be used for the test:
1.
Halon 1301 should not be used as a test agent. Availability of
Ha]on 1301 is limited by the Montreal Protocol on Substances that
Deplete the Ozone layer. Use of Ha]on 1301 as a test agent further,
reduces availability for fire extinguishing purpose. As such this '.
standard recommends that Ha]on 1"301 should not be used as a test
agent.
(Log # 70)
12A-23- (2.13 (New)): Reject
SUBMrrrER: David Saum and J o h n Hupman, INFILTEC "
RECOMMENDATION: Add new section on .Enclosure Notice
(2.137)
"2.13 Enclosure Notice. After the completion of a door fan test a
written notice of the test and its requirements shall be posted in the
enclosure. The notice shall include the following ore equivalent:
This room is protected with a Halon 1301 fire suppre_sslon system.
To be effective in a fire emergency the halon 1301gas must be
567
NFPA 12A ~
A92 TCR
Minutes from Alt- Test Agents Sub-committee Meeting, April 3,
1989.
W.ysocki, T., "SF6 ~..H-1301 Pipeline Flow A Preliminary Study,"
private commumcauon.
Copies of the unpublished reports and the private communication
are provided with this proposal.
COMMITI'EE ACTION: Accept in Principle.
A-1-7.4 Where circumstances exist that require a discharge test, test
agents sulfurhexafluoride or Halon 121 may be used. These agents
have been identified as having characteristics similar to Halon1301.
Paragraph A Same
Paragraph B Same
Paragraph C:I Paragraph 1 Sentence 1 deleted.
Paragraph C:I Paragraph 2 delete.
Replace C.2 with
2.
When using SF6 the following information shold be used for
guidance.
(a) Enclosure leakage rate of SF6 dispersed in air is nearly
identical to Halon 1301.
(b) Disribution in balanced and unbalanced systems is very
similar to Halon 1"301.
(c) Sulfur hexafluoride is compatible with Halon 1301 systems
hardware.
(d) The toxicity of sulfur hexafluoride is no greater than that of
Halon 1301.
(e) The vapor densities alone and in mixtures with air are nearly
identical to Halon 1301.
(f) The dynamic loads exerted on the piping network will be
similar to that of Halon 1301.
(g) The test cylinder for sulfur hexafiuoride should be filled to
9 8 % o f the Halon 1301 weight.
(h) Test cylinders for 360 psig applications filled with sulfur =
hexafluoride will not meet DOT regulations for shipping. Filling
must be performed at the job site.
(i) The test meters should be calibrated with a sample of sulfur
hexafluoride in air. Meters used to measure Halon 1301"concentra.
tions are suitable for this puriSose , but the response to sulfur
hexafluoride is longer.
(j) Sulfur hexafluoride is not a fire extinguishing agent.
(k) Sulfur hexafluoride should not be used or stored in 360 psig
cylinders where the ambient temperature exceeds 100°F.
(1) Sulfur hexafluoride ozone depletion is zero and not
regulated by the Montreal Protocol.
Of the simuhints that are available for discharge testing Halon 1301
systems, sulfur hexafluoride is the best, non-ozone depleting
alternative. Halon 122 (CFC 12) should not be used because it has
been identified as an ozone depleting chemical and its availability is
limited by the Montreal Protocol. Halon 121 (HCFC 22), while not a
major contributor to ozone depletion, poorly mimics the leakage of
1301 when dispersed into the enclosure and is not compatible with all
hardware. As such this standard recommends that, when full
discharges are required by the authority havingjurisdiction, sulfur
hexafluoride should be used as the test agent.
2.
A comparison of sulfur hexafluoride and Halon 1301 follows:
(a) Enclosure leakage rates of the two materials dispersed in air
are nearly identical.
(h) Distribution in balances and unbalanced systems is very
similar.
(c) Sulfur hexafluroide is compatible with Halon 1301 system
hardware.
(d) The toxicity of sulfur hexafluoride is no greater than that of
Halon 1301.
(e) The vapor densities of the two materials alone and in
mixtures with mr are nearly identical.
(f) The dynamic loads exerted on the piping ne~zvork will be
similar.
(g) The test cylinder for sulfur hexafluoride should be filled to
9 8 % o f the Halon 1301 weight.
(h) Test cylinders (for360 psig applications) filled with sulfur
hexafiuoride will not meet DOTregulations for shipping. Filling
must be performed at the job site.
(i) The test meters should be calibrated with a sample of sulfur
hexafluoride in air. Meters used to measure Halon 1301concentrations are suitable for this purpose, but the response to sulfur
hexafiuoride is lower.
(j) Sulfur hexafluo.ride is not a fire extinguishing agent."
SUBSTANTIATION: Insuring that a particular enclosure is
adequately protected can be accomplished by several procedures,
including the room integrity test (i.e., tfae door fan method). If the
geometry of the enclosure and the piping system used to deliver the
1301 to the enclosure are complex or if the enclosure contains
obstructions or if floor to ceiling walls do not surround the area to be
protected (as in the case of a room with a suspended ceiling with a
common airplenum), then the best procedure to insure adequate
protection of the area is a discharge test. Even though mounung
concerns over the release of Halon 1301 into the atmosphere have
precluded the use of the agent for discharge testing, these tests can
still be undertaken by using an alternate agent to simulate the Halon
1301. Alternative test agent or simulants the Halon 1301. Alternative
test discharge test provided that the agent closely mimics the behavior
of 1301 in the discharge test and is compatible with system hardware.
Of the simulants that are available for discharge testing Halon 1301
systems, sulfur hexafluoride is the best, non-ozone depleting
alternative. Halon 122 (CFC 12) should not be used because it has
been identified as an ozone depleting chemical and its availablity is
limited by the Montreal Protocol. Furthermore Halon 122 poorly
mimics the behavior of 1301 in discharge tests. Halon 121 (HCFC
22), while not a major contributor to ozone depletion, poorly mimics
the leakage of 130Iwhen dispersed into the enclosure and is not
compatible with all hardware.
Sulfur hexafluoride is non-toxic. SCUBA equipment is not needed
during normal discharge tests. The gas is also a very good insulator
therefore itwill not effect sensitive electronic equipment. Sulfur
hexafluoride is compatible with the hardware and materialsof
construction used in Halon 1301 equipment. The cost of sulfur
hexafluoride is comparable to Halon 1301.
Since sulfur hexafiuoride's vapor, density and other physical
properties are very similar to 1301 s, the behavior of the two materials
d u n n g discharge tests are similar. Enclosure leakage rates of the
materials dispersed in air are nearly identical.
The only drawback to using sulfur hexafiuoride is that the low
pressure containers used for 1301 (360 psig systems) are not
adequate for transporting the gas. The low pressure Halon containers can be safely filled and used for the test provided they are not
exposed to temperatures in excess of about 100°F. This difference is
a result of the lower critical temperature and higher vapor pressure
for sulfur hexafluoride as compare to 1301.
The. following documents are cited as supporting evidence for this
proposal:
Anderson, S.O., "Halons and the Stratospheric Ozone Issue," Fire
Journal, 81 (1987).
DiNenno, PJ., et al "Evaluation of Halon 1301 Test Gas Simulants:
Enclosure Leakage,* Fire Technology, February, 1989.
DiNenno, P.J., et al "Discharge System Tests of Halon 1301 Test Gas
Simuiants," unpublished report.
DiNenno, P.J., et al ~Fireline Corporation Discharge Tests,
unpublished report,
Existing 3 is changed to 4.
New 3. When using Halon 121 the following information should be
used forguidance.
(a) Because of its lower vapor density the enclosure leakage rate
of Halon 121 is slower than for Halon 1301.
(b) Distribution in balanced and many unbalanced systems is
similar to Halon 1301. Hydraulically complex systems may not be
suitable for testing with this agent.
(c) Common materials of consturction are satisfactory for use
with Halon 121. However, the compatibilitywith exposed Buna-N
seals should be established for the duration of storage.
(d) Self contained breathing apparatus must be used ff personnel enter the protected space while the agent is present. The
threshold limit value for Halon 121 is 1,000 ppm by volume.
(e) The dynamic loads expected on the piping network will be
similar to that of Halon 1301.
(0
The test cylinders should be filled to 58% of the Halon 1301
wieght to achieve the same volumepercent concentration.
(g) Concentrations determinedby a meter calibrated for Halon
1301 must be scaled by a factor in the range of 1.3 to 1.4.
(h) The ozone depleting potential o f I-Ialon 121 is low (0.050
DP). It is not regulated by the Montreal Protocol of 1987.
(i)
The suitability of Halon 121 at minimum cylinder fill
densities has not been determined.
(j)
Halon 121 is not a recognized fire extinguishing agent.
COMMITrEE STATEMENT: The committee assigned an ad hoc
subcommittee to develop the above text. The text was added to
provide guidance on simulant test gases.
(See proposal 12A-122, paragraph A-4-7).
(Log # 89)
12A- 27 - (A-1-7.4 C.1): Reject
SUBMITI'ER: Brendan Reid, Retrotec
RECOMMENDATION: Delete references to HCFC 22 as a candidate
alternate test material. Proposed new wording of the second
paragraph:
"Sulphur hexafluoride has been identified and is currently being
evaluated as a candidate alternate test material."
568
NFPA 12A -- A92 TCR
SUBSTANTIATION: It is not appropriate for the fire protection "
indusL-/to consider a substance for new applicationswhich has any
possible negative effect on the ozone layer m non-CFC candidate is
available. The tacit acceptance by regulators of HCFC's for new
applications is predicated on their use as "bridging" chemicals until a
non-CFC substitute is found. This appears to b-e the case with
alternate discharge agents.
COMMITTEE ACTION: Reject. (see proposal 12A-122, paragraph
A-4-7).
COMMrFrEE STATEMENT: Refer to action on Proposal 12A-26
(Log #69).
I~A- 32 - (A-I~10.1): Reject
(LOg # 12)
SUBMITI'ER: William Eckholm, FSSA
RECOMMENDATION: Delete second sentence.
SUBSTANTIATION: The present second sentence does not agree
with the ASTM B31.1 methodology given in A-I-10.1.1
COMMITTEE AErION: Reject.
The submitter's proposal is insufficient and therefore the committee
was unable to make an informed decision.
(Log # 33)
12A-33-(A-I-II.I (2) (c) (New)): Accept in Principle
SUBMITTER: William Eckholm, FSSA
RECOMMENDATION: Add new paragraph (c) as follows:
"The charging, recharging of cylinders, or the removal or transfer of
agent shall be done using a closed loop system. A closed loop system
is defined as a system which permits transfer of halon between supply
cylinders, system cylinders, and recovery cylinders, without loss o f halon to the atmosphere."
SUBSTANTIATION: Proposed wording described a system to
reduce halon emissions (ozone depletion question).
COMMITTEE ACTION:, Accept in PrincilSle.
'
Add the following:
A-4-1.4 The charging, recharging of cyLinders, or the removal or
transfer of agent should be done using a closed loop system. A closed
loop systempermits transfer of halon between supply cylinders,
system cylinders, and recovery cylinders, with only minor loss of halon
to the atmosphere. (See proposal 12A-122, paragraph A-4-1.3).
COMMITTEE STATEMENT: Relocation and editorial corrections.
(Log # 23)
12A- 28 - (A-1-7.4 E.1): Accept
SUBMITTER: William Eckholm, FSSA
RECOMMENDATION: Revise to read:'
"Halon analyzers should be field calibrated and adjusted, in "
accordance with the analyzer manufacturer s instructions, prior to
each use."
SUBSTANTIATION: Clariflcationl
COMMITTEE ACTION: Accept. (See proposal 12A-122, paragraph
A-4-7).
(LOg # 11)
lEA.-29 - (A-1-9.4): Accept
SUBMrrTER: William Eckholm, FSSA
RECOMMENDATION: Revise second sentence to read:
"Generally, steel cylinders meeting US Department of Transportation requirements will be used. Manifoldedcylinders are used for
large installations."
SUBSTANTIATION: The present reference to "100 lb (45Xkg)
Halon 1301" capacity is obsolete. Single cylinders orS00 lb (and
~%eater) are common in today's usage.
MMrFrEE ACTION: Accept. (See proposal 12A-122, paragraph
A-2-1.4).
12A- 34 - (A-2.1.1.3): Accept in Principle
(Log # 34)
SUB~:
William Eckholm, FSSA
RECOMMENDATION: Delete "magnetic tape storage areas" and
"records centers" from list of examples of not normally occupied
areas."
(Log # 32)
12A-30- (Figures A-1-9.4 (a),~(b), and (c)): Reject
SUBIVu'I'r~tR: William Eckholm, FSSA '
RECOMMENDATION: Enlarge and make these figures more
readable.
SUBSTANTIATION: Editorial Comment
COMMITTEE ACTION: Reject.
COMMI'ITEE STATEMENT: Proposal addressed TCR figures. The
1989 edition of NFPA 12A contains figures on adequate size.
(Log# 3)
(Log# 4)
_%+x.=1
,~=1-x..
Ideal Solution Law applies as X H 1
PH = Pv XH
--P (z-x~)
,
12A- 35 - (A-2-2.2.3): Reject
SUB~:
William 1L Collier, Interstitial Systems, Inc.
RECOMMENDATIONE Add the following new sentence to the end
of this section:
"Conversely Halon 1301 Total Flooding; discharge systems are not
required beneath the raised floor when the low voltage, data, voice,
signal, interconnecting cables and/or high voltage lines and the like
are removed from the air su'eam by means of a wlreway and/or a
raised floor wireway, therefore creating dedicated air plenum and/or
a sterile environment.
SUBSTANTIATION: Typically the single cavity beneath a raised
floor encompasses line voltage wiring in a protective sheathing,
however, low voltage i.e., voice, data, signm, interconnecting
computer cables and the like are unprotected and recklessl), exposed
to a conditioned air stream resulting in a potentiaily hazardous
environment.
NFPA 75, Section 2-4.3(a) An automatic detection and extingui~hin~ system is utilized in the space beneath a raised floor only if the
raised floor itself is combustible. NFPA 12A does not require the
detection or flooding of areas inside conduit wireways or the like: the
inherent function o f such enclosures is to actuate electrical protective
devices and disconnecting means.
The air plenum becomes a sterile *environment precluding a
requirement for suppression agents.
In light ff the 1985UL listing for Infinity "A Raised Floor Wireway"
listing #E90871 (N); its compliance withNEC Article 632; its
recognition as a wireway under Article 362 and 645-2 (c)(2)i; the
current EPA investigation and limitation of Halon production; the
NFPA 90A-1990 conclusion to eliminate wiring in an air stream and
the growin~ popularity and recognition as this being a superior
means of wrong cooling and constructing implies ongoing use;
therefore a clarification by means of this proposal wil! qualify design
12A- 31 - (A-I-9.4): Reject
SUBMITTER: Joseph A. Senecai, Ashland, MA
RECOMMENDATION: Change the equation for cal.culation for
nitrogen partial pressure from:
P =(1-X,)P,toPn=P-(1-Xn)P
SUBSTANTIATION: Deviation of this equation is quite simple. I
believe the omission of the "-" sign was probably a typesetting
problem. P = Pn + PH
where:
P --=Total pressure
Pn Nitro{ten partial pressure
P. = H-13~1 parual pressure
P% H-1301 vauor pressure
X[n = N make ~T-actionin
solution
.
,
XH - H?1301 make fracuon m solution
P,=P.P
,
SUBSTANTIATION: In a computer center operating environment,
these areas are often occupied. They should not be considered as
"normally unoccupied."
COMMIT1T_.E ACTION: Accept in Principle.
Material moved to definitions. Areas in proposal were deleted. (See
proposal 12A-122, paragraph I-3.1)
" ,
'
COMMITTEE STATEMENT: Normally occupied is now clearly
defined.
o
(I-X,)
RAWMARK at70 F, P = 360 Psi X, = 0.035
X~--= 0.965
COMMrITEE ACTION: Reject.
COMblrIq'EE STATEMENT: Current edition contains the
correction.
569
NFPA 12A -- A92 TCR
I
SUBSTANTIATION: There should be a note of common sense
injected at the beginning of this procedure.
C O M M r r r ~ ACTION: Accept in Principle.
Add 13-1.1.4 as follows:
"B-1.1.4 This procedure should not be considered to be an exact
model of a discharge test.. The complexity of this procedure should
not obscure the fact that most failures to hold concentration are due
to leaks in the lower surfaces of the enclosure, but the door fan does
not differentiate between upper and lower leaks. The door fan
provides a worst case leakage estimate that is very useful for enclosures with complex hidden leaks, but it will generally require more
sealing than is necessary to pass a discharge test. To provide the
highest margin of protection, do not perform a d o o r fan test until the
lower surface of the enclosure has been sealed.
COMMrITEE STATEMENT: Clarification.
and engineering techniques when a raised floor wire~,'ay is utilized in
a facility intending to incorporate Halon 1301 into an EDP facility or
the like.
C o M M r r T E E ACTION: Reject.
COMMITTEE STATEMENT: Beyond the scope of this standard.
This is a use and application issue.
(Log # 35)
"12A- 36- (A-2-2.2.3): Reject
SUBMITrER: William Ecltholm, FSSA
RECOMMENDATION: Delete entire paragraph.
SUBSTANTIATION: "Underfloor only" systems are within present
design capability. Such systems have been fire tested with satisfactory
results.
C O M M r r r E E ACTION: Reject.
COMMITrEE STATEMENT: The substantiation conflicts with the
rationale in paragraph 2-2.2.3.
(Log # 15)
12A. 41 - (B-1.2.1.2): Reject
SUBMITrER: William Eckholm, FSSA
RECOMMENDATION: Delete entire paragraph.
SUBSTANTIATION: The paragraph implies that a satisfactory haion
system cannot be designed unlessbarriers are provided above t h e false
ceiling; when in fact the barriers are required only to conduct the
door fan test.
C O M M r r r E E ACTIOIN: Reject.
COMMrITEE STATEMENT: Existing text does not imply this.
(Log # 13)
12A* 37 - (Table A-2-5,3): Reject
SUBMITTER: William Eckholm, FSSA
RECOMMENDATION: Enlarge table to give correction factors
down to 1000 ft.
Altitude
Correction Factor
feet
meters
1000
305
.98
2000
609
.94
SUBSTANTIATION: Reduction allows conservation of agent for
tems installed at altitudes of 1000 to 3000 ft.
MM1TrEE Ac'rION: Reject.
C o M M r r T E E STATEMENT. The source of the proposed material
could not be determined nor the data verified.
(Log # 97)
12A- 42 - (]3-1.2.1.2): Accept in Principle
SUBMI'rrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Delete the, last clause starting with " a r e . . . "
and replace with "may be so conservative as to fail performance
criteria whereas they may be capable of retaining halon for the
required time."
SUBSTANTIATION: Absence of containing barriers will probably,
although not always, guarantee test failure, f f t h e room can pass the
integrity test as is or with temporary false ceiling barriers in place to
measure BCLA per the proposed section 13-2.6.2.9 dated September
8, 1989, then it shouldl With excess ceiling leaks flit passes the
conservative integrity test it should pass a discharge test with flying ,
colorsl
COMMITTEE ACTION: Accept in Principle.
COMMITTEE STATEMENT: Refer to action on Proposal 12A-40
(Log #72).
(Log # 14)
12A- 38 - (B-I.I.1): Reject
SUBMTrrER: William Eckholm, FSSA
RECOMMENDATION: Add to present paragraph:
"rhisprocedure requires that the enclosure be fabricated with "slab
to slab" perimeter walls.
SUBSTANTIATION: The added wording defines a necessary
limitation of the test procedure.
C O M M r r r E E ACTION: Reject.
This is covered in 13-1-2.1.2.
(Log # 75)
12A- 43 - (B-1.2.1.5): Accept in Principle
SUBMrlTER: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Add to section 13-1-2.1.5 on Static Pressures
after minimized:
=during the door fan test and during a halon discharge.
If permanent sealing can not minimize the problem, then building
HVAC systems serving the room should be shut down, and room
HVAC systems pressurizingunder raised floors should be shut down."
SUBSTANTIATION: HVAC systems can.produce differential
pressures across enclosure surfaces which can have major influence
on halon retention. Building HVAC will often cause different
pressures across each wall and these will be highly dependent on
whether door are open or closed. Since duct pressures are high
dampers are often inadequate to reduce the pressures below levels
that will impact halon leakage. HVAC system-s that provide air
beneath rinsed floors generally pressurize below the floor and the
door fan test will not be able to simulate this pressure which will
exaggerate lower leaks.
COMMITTEE ACTION: Accept in Principle.
Add the following to B-1.2.1.5:
"...during the door fan test. The test can only be relied upon for
enclosures having a range of static pressures outlined in B-2.5.2.3."
COMMrrFEE STATEMENT: Clarification.
(Log # 96)
12A- 39 - (B-I.I.1): Accept
SUBMITrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Change last sentence to:
" r h e calculation methbd provided makes it possible to predict the
time it will take for a descending interface to fall to a given height or
for the continually mixed cases the time for the concentration to fall
to a given percentage concentration."
SUBSTANTIATION: The formulae predict time to a height not the
other way around. If the proposal for continuous mixing occurs in
section 13-2.5.1.6 (or other section) the additional comment or fall to
concentration will be required.
COMMITrEE ACTION: Accept.
(Log # 72)
12A- 40 - (B-l.l.4 (New)): Accept in Principle
'
SUBMITTER: David Saum a n d J o h n Hupman, INFILTEC
RECOMMENDATION: Add new section B-l.l.4 in Scope section:
"I3-1.1.4 The complexity of this procedure should not obscure the
fact that most failures t o h o l d concentration are due to leaks in the
lower surfaces of the enclosure, but the door fan does not differentiate between upper and lower leaks. If the lower surfaces of the
enclosure are carefully inspected and sealed, the enclosure will not
leak halon, despite any door fan estimates to the contrary. The door
fan provides a worst case estimate leakage estimate that is very useful
for enclosures with complex hidden leaks, but it will generally require
more sealing than is necessary to pass a discharge test. To provide
the highest margin of protection, do not perform a door fan test until
the lower surface of the enclosure has been sealed."
i
I
570
i
(Log # 102)
12A- 44 - (B-1-2.2.2): Accept
SUBMFFrER: James M. Rucci, Harrington Group, Inc.
ECOMMENDATION: Revise first sentence as follows:
~There can be no significant attached volumes within or adjoining
the enclosure envelope that will allow detrimental halon leakage that
would not be measured by the door fan."
NFPA 12A n
SUBSTANTIATION: This change makes it clear that the attached
volume may either be adjacent to the enclosure envelope or
completely surrounded by the halon protected area.
COMMFFFEE ACTION: Accept.
(Log #
12A- 45 - (B-1.2.2.4): Accept in Principle
SUBlVI1TFER: Boman Mama, Department of Transport
RECOMMENDATION: Consider allowing for leak locations other
A92 TCR
12A- 47 - (13-1.2.3.5): Accept
SUBMrITEI~ Technical Committee on Halogenated Fire Extinguishing Systems
RECOMMENDATION: Delete last sentence "Mechanical m i x i n g . . .
considered."
• SUBSTANTIATION: To conform to log #95, ]5-2.7.1.6.
COMMFFFEE AGTION: Accept.
I
6)
• (Log # 66)
12A. 48 - (B-1.2,3.5): Reject
SUBI~HTI'JKR: R.A. Whiteley, Wormald
RECOMMENDATION: Delete "1/2 the design concentration and
add:
"80 percent of the desilgrl, concentration or as otherwise specified by
the authority having jurisdiction."
•
SUBSTANTIATION: There is not a 100 percent safety factor on the
extinguishing concentration of all fuels. The minimum safety factor,
is 20 percent i.e., 80 percent of the design concentration. This,
therefore should be the minimum acceptable concentration.
than worse-c&~.
SUBSTANTIATION: We have one major reservation concerning the
proposed methodology, this relates to thepresumption that the
~pehures as measuredwill be distributed 50:50 between the floor and
ceiling. Whilst this is recognized as being the worst case, and
therefore a failsafe assumption, it is likely to be true only in the most
exceptional of cases. We have heard instances of 1 in 10,000
enclosures being quoted. Whilst we support the desire not to
overpredlct retenuon time we consider that the proposal is unduly
onerous as it will lead to a situation where many rooms will be
reported to be insufficiendy tight despite the fact that if they had
been discharge tested they would have been satisfactory. Corrective
sealing of such enclosures can be a time consuming and expensive
exerciseparticularly where deadlines are involved. It therefore seems
inequitable to require such corrective sealing where the fault lies not
with the enclosure but with the imprecision of the retention time
calculation methodolo - Discussions
with authori'ties havin
.
. g
jurisdiction with the u~Yindlcate that they also support this argument
and will be unwilling to adopt NFPA methodology as give a predicted
retention time that ~s closer to the likely discharge test retention time
figure in most cases rather than one thatgave safe-side answers in all
cases. In this connection we would consider a method that predicted
retention time is < 10 minutes in up to 5 percentage of examples as
acceptable. To put this issue into perspective it should be borne in
m i n d that the commonly used 10 minute retention tirde criterion is
not any sort of masic number, it is an arbi~ry line that has been
drawn to help mimmise the risk or reignition of an enclosure fire.
The adoption of a 6, 8 or 15 minute criterion instead would probably
have minimal influence upon the occ.urrence of reignition in real fire
situations.
Having stated our desire to see more realistic data for leakage
location used, we need to address the problem of how that can be
achieved. Ideally this could be done by determining what would be
the most likely leakage positions for different types of construction
and enclosure use and embodying these figures in the calculation
method. We doubt however, whether there is currently sufficient
information available to determine this with any accuracy ori an
average basis. We therefore rely on the experience of the operator to
assign values and positions for the high/low subjectivity into the
method this can be minimised by inteUigent use of techniques such as
t e m p o r a ~ sealing of suspected leakage paths to quantify leakage area
contribuuon, the use of balancing techniques (BCLA)penetrations.
Obviously where an informed judgment cannot be made we revert to
worst case assumptions.
Our experience of permitting this degree of operator judgment has
not to date given rise to any overpredicdons of retention time where
correlation discharge testing data is also available.
COMMITTEE ACTION: Accept in,Principle•
COMMITTEE STATEMENT: Refer to acuon on Proposal 12A-21
(Log #85).
COMMITTEE ACTION: Reject.
COMMITTEE STATEMENT: No current method of calculation.
12A- 49 - (B-1.2.3.10): Accept
SUBMrI'TER: Technical Committee on Halogenated Fire Extinguishing Systems
COMMENDATION: Add:
"If a suspended ceiling exists, it is assumed that the halon discharge
will not result in displacement of the ceiling tiles. Increased
confidence may be obtained if ceiling tiles are clipped within four
feet of the nozzles and all perimeter tiles."
SUBSTANTIATION: This is an existing assumption which must be
stated. Its implementation partially satisfies the intent of Proposal
12A-98 (Log #71).
COMMFrTEE ACTION: Accept. '
12A- 50 - (B-1.3): Accept
SUBMITrER: Technical Committee on Halogenated Fire Extin~j~shing Systems
COMMENDATION: Add:
"Minimum Halon Protected Height. The minimum acceptable
height from the floor slab to which the descending interface is
allowed to fall during the retention time, as specified by the authority
having jurisdiction."
SUBSTANTIATION: Clarification.
COMMITFEE ACTION: Accept.
~
12A- 51 - (B~I.3): Accept
SUBMITrEI~a Technical Committee on Halogenated Fire Exdnshing Systems
COMMENDATION: Add:
"Maximum Halon Protected Height. The design height of the
halon column from the floor slab. This does not include the height
of unprotected ceiling spaces. *
SUBSTANTIATION: Clarification.
COMMrrI'EE ACTION: Accept.
~
(Log # 77)
12A- 46 - (B-1.2.2.3): Accept in Principle
SUBMITTER: David Saum a n d J o h n H u p m a n , INFILTEC
RECOMMENDATION: Add to section B-1.2.3 Return Path:
"Return paths from all of the surfaces of the enclosure should be
established and documented. This includes opening doors in all
adjacent rooms to halls which are in contact vath the door fan; and
opening doors to upper to rooms above and below the enclosure to
stairwells or.shafts that connect to the hall with the fan. Enclosures
with walls to the outside present a special problem because of thepotential problems from wind or stack pressures and the lack of
access to external doors. Large rooms with leakage areas comparable
the door areas may require more than one hallway or door opening
for an unrestrictedreturn path."
SUBSTANTIATION: The present explanation of return path is too
vague to provide guidance.
COMMITI'EE ACTION: Accept in Principle.
COMMYITEE STATEMENT: Refer to acuon on Proposal 12A-53
(Log #37).
(Log # 36)
12A- 52 - (B-1.3): Accept in Principle .
SUBM1TTER: Colin Genge, Shehair Scientific, Ltd.
RECOMMENDATION: Delete Floor Area: Plan area for a known
elevation.
SUBSTANTIATION: This conflicts with 13-1.9.3.4.
COMMITI'F~ ACTION: Accept in Principle.
Accept the submitter's recommendation and add:
"Effective Floor Area. The volume divided by the maximum halon
rotected hei hr."
P C O ~
STATEMY-.NT: Clarification.
(Log # 57)
12A- 53 - (B-1.3): Accept in Principle
SUBMITI'ER: Colin Genge, Sheltair Scientific, Ltd.
571
NFPA 12A -- A92 TCR
RECOMMENDATION: Change ~ReliefArea" to Relief Zone".
SUBSTANTIATION: The definition currently following relief area
does not describe the relief area at all but rathei" a zone surrounding
the enclosure. Having a definition of this zone is important. A
separate definition of teller area is on another proposal form.
I COMMITTEE ACTION: Accept in Principle.
Change "Relief Area" to "Return Path Space".
COMMITrEE STATEMENT: Clarification.
(b) Summary of changes in B-2.7.1.7: Change thi.• calculation of
hold time to include an error bound on each estimate that is based
on flow and pressure gauge errors.
SUBSTANTIATION: The current specifications for gauge accuracy
are unrealistic and do not encourage the use of more accurate
equipment. If the gauge accuracy was specified at a realistic accuracy
that was tied to the manufacturers estimate, and that accuracy was
used to compute the error bounds of the halon hold time estimate,
then we would appreciate the experimental bounds of the present
equipment. Dwyer Magnahelic 60 Pa gauges are rated at 4 percent of
full st..ale or about +/-2.5 Pa. Although some manufacturers make an
attempt to recalibrate the gauges, even though Dwyer does not
recommend it, there are major additional problems with hysteresis
and the inherent difficulty of reading analog gauges. For that reason
we suggest that the best accuracy obtainable from a magnahelic is
about 3 p e r c e n t FS or about 2 Pa. Note that this is a 20 percent error
at the typical halon test pressureI
COMMITTEE ACTION: Reject.
COMMITTEE STATEMENT: No text provided for the major points.
(Log # 38)
12A- 54 - (B-1.3 and B-2.1): Accept in Princip.le
SUBMrlWER: Colin Genge, Sheltair Scienufic, Ltd.
RECOMMENDATION: Change text for Relief Area to:
"Relief Area: The effective flow area that the air being blown by the
door fan must travel through to complete a return path back to the
leak.
Delete from B-2.1 the "backflow" to match relief area definition.
SUBSTANTIATION: This important concept should be defined and
should be used elsewhere in the standard.
COMM1TrEE ACTION: Accept in Principle.
Change text for Relief Area to Return Path Area. The effective flow
area that the air being moved by the door fan must travel through to
complete a return path back to the leak.
In paragraph B-2A change 0) to the following:
"(j) Determine the existence of adequate return path area outside
the enclosure envelope used to accept or supply the door fan area.
COMMrlWEE STATEMENT: Clarification.
(Log # 101)
12A- 55 - (13-1.3): Accept in Principle
SUBMrrrER: James M. Rued, Harrington Group, Inc.
RECOMMENDATION: Revise the definition of Attached Volumes as
follows:
"A space within or which adjoins the enclosure envelope that is not
grotected by halon."
UBSTANTIATION: Current text implies that an Attached Volume
must fall within the enclosure envelope.
C O M M r r r E E AC'rlON: Accept in Principle.
Accept the submitter's recommendation and add:
"... and cannot be provided with a clearly defined return path."
COMMITFEE STATEMENT: Clarification.
(Log # 103)
12A- 56 - (B-2.1): Accept
SUBMITI'ER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Add the following text:
"(1) obtain appropriate architectural, I-IVAC, and halon system
design d o c u m e n t s . "
SUBSTANTIATION: The current text does not clearly indicate that
these documents are necessary in order to establish test parameters
and potential difficulties with conducting the tests.
COMMITTEE ACI~ION: Accept.
(Log # 104)
12A- 57- (B-2.2.1.1): Accept
SUBMHTER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Revise the current text toread as follows:
"The door fan or fans should have a total air flow capacity capable of
producing a pressure difference at least equal to the predicted
column pressure or 10 Pa, whichever is greater."
SUBSTANTIATION: A minimum test pressure of 10 Pa is required
in section I3-2.6.1.3. The predicted column pressure may be less than
this value.
COMMITTEE ACTION: Accept.
(Log # 80)
12A- 58 - (B-2.2.1.5 and B-2.7.1.7): Reject
SUBMrIWER: David Saum a n d J o h n H u p m a n , INFILTEC
RECOMMENDATION: Revise Section B-2.2.1.5 and B-2.7.1.7
(incomplete text available):
(a) In B-2.2.1.5 change "It should have an accuracy of +/-1 Pa and
divisions of 1 Pa or less" to -The manufacturer's rating of gauge
accuracy should be used and this accuracy should be used for
computation of error bounds."
I.
(Log # 105)
12A- 59 - (B-2.2.2): Accept in Principle
SUBMITTER: James M. Rucci, Harrington Group, Inc.
RECO~ATION:
Revise the current text as follows:
Change (a) to read "smoke pencil, fully charged (See Caution),
Add the following caution statement following (1):
CAUTION: Use of chemically generated smoke as a means of leak
detection may result in activation of building or halon system smoke
detectors. Appropriate precautions shall be taken. Due to corrosive
nature of the smoke, it shall be used sparingly..'
SUBSTANTIATION: This caution statement is necessary as a
reminder that smoke detector activation may occur in the process of
leak detection. The effects of halon system activation and building
fire alarm activation must be considered.
COMMITTEE ACTION: Accept in Principle.
Accept the submitter's recommendation and change "shall" to
"should" in the recommended text.
COMMYITEE STATEMENT: Editorial.
(Log # 73)
IRA.- 60. (13-2.2.3.1, B-2.2.3.3, B-2.2.3.6, and lg2.2.3.7): Accept in
Principle
SUBMrrTER: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: In section 13-2.2.3.1, change "overall" to
"single point system." Add a final sentence "This technique has not
been tested u n d e r controlled conditions and it is unclear whether it
can provide accurate estimates of the calibration accuracy specified
elsewhere in this procedure."
In section ]3-2.2.3.3 change "cardboard" to "rigid material" in several
places.
In section 13-9.2.3.3 and 13-2.2.3.6 change "12 in. by 12 in." to "about
one sq ft, sharp edged" in several places.
In section B-2.2.3.7 change "15%" to a number that can be related
to the fan and gauge accuracy, and experimental data under
controlled conditions.
SUBSTANTIATION: The Field Calibration Check tests the door fan
system at a single calibration point which is at the low end of its
performance range.. It can be ~hown that a door fan could meet the
calibration requirements stated elsewhere in this document and still
fail this test. Some controlled tests should be made to document the
udlity of this test, and the contradiction between the Field Check and
the measurement error specifications should be resolved. The orifice
material is not as important as its rigidity so that it can present a
square sharp edge to the air flow. In addition, the optimum hole
shape is round Idthough a square hole is probably satisfactory. This
should probably be tested as well.
COMMrIWEE ACTION: Accept in Principle.
.1. Replace 13-9.2.3.1 with the following:
"B-2-2.3.1 .This procedure enables the authority havingjurisdicdon
to obtain an indication of the door fan and system calibi'ation
• accuracy upon request."
2. Replace B-2.2.3.3 with the following:
"13-2.2.3.3 Install a piece of rigid material less than I / 8 in. in
thickness (free of any penetrauons) in an unused blower port or
other convenient enclosure opening large enough to accept an
approximately .I square meter sharp edge r o u n d or square opening.
Tape or secure the cardboard firmly into place."
3. Replace B-2.2.3.6 with the following:
13-2.2.3.6 Create a sharp edged, round or square opening of .1 m
in the rigid material. Measure and cut a square approximately .1
572
NFPA 12A -- A92 TCR
SUBSTANTIATION: The text does not make it clear that the net
volume should always be used such that the greatest possible h a l o n /
air mixture density will be used in the time prediction calculations.
COMMITrEEACTION: Accept in Principle.
Add the following to B-2.3.2.1:
"Deduct the volume of large solid objects to obtain the net volume."
COMMITTEE STATEMENT: More technically correct-
J square meter sharp edge round or square opening in the cardboard.
Adjust the blower to the previously used positive or negative pressure
differential. Measure the flows and calculate an average ELA value
using section B-2.6.3."
COMMITTEE STATEMENT: Revised for clarification. The 15
percent requirement was not changed as it meets the pre-established
cumulative accuracy requirements as well as achievable field testing
resolution.
(Log # 107)
12A- 66 - (B-2.3.2.3): Accept in-Principle
SUBM1TrER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Change the word "total" to "net.".
SUBSTANTIATION: The text does hoe make it clear that the net
volume should always be used.
COMMITTEE ACTION: Accept in Principle.
Replace B-2.3.2.3 with the following:
"B-2.3.2.3 Calculate the effective floor area by dividing the net
halon protected volume by the maximum halon protected enclosdre
height."
COMMITI'EE STATEMENT: Clarification and consistency of terms.
(Log # 39)
12A- 61 - (B-2.2.3.4): Accept in Principle
SUBMrrrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Delete the original text and change to:
"With the door fan coi'rectly installed adjust the flow rate to achieve
a convenient pressure differential between 10 and 15 Pa.
SUBSTANTIATION: The original text is confusing. The meaning of
"turned" is not clear. The range should extend between 10 to 15 in
order to pin the range down more precisely. Readings below 10
introduce more chances for error butwe allow them with the use of
the word "convenient-"
COMMITTEE ACTION: Accept in Principle.
"
COMMITTEE STATEMENT: Refer to acuon in Proposal 12A-60
(Log #73).
(Log # 40)
12A- 62 - (B-2.2.3.5): Accept in Principle
S U B I ~ Y I ~ q : Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Add:
~i'his ELA should be less than 3 sq ft.
SUBSTANTIATION: Measilring an existing hole of 3 sq ft with the
required accuracy of 5 percent could yield a 3 X..05 = 15sq ft error.
When measuring the 1 sqft hole this 0.15 ~ ft error would equal the
total allowable error of-'- 15 percent. An emsting hole over 3 sq ft
should therefore not be incorporated into thistest.
C O M M x t - t ~ g A C T I O N : Accept in Principle.
Replace B-2.2,3.5with the following:
"B-2-2.3.5 At the pressure achieved, measure the flow and calibrate
an initialE L A value using 13-2.6.3.Repeat the E L A measurement
under positivel~,essureand average the two results. This E L A should
be lessthan 3 ft"."
COMMIYIJ::E S T A T E M E N T : Added material conforms to normal
testprocedure.
°
12A- 67 - (B-2.3.3.3): Accept'(Log # 42)
SUBMITTER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: The new 2.3.3.3 should read:
"Secure all doorways and openings as for a halon discharge. Post
personnel to ensure they stay shut/open.
Open doorways inside halon protected enclosure even though they
may be closed upon discharge."
Delete everything else from this section.
SUBSTANTIATION: The first two sentences from this section do
not apply at this stage beause the static pressure at time of halon
discharge must bi~ measured in B-2.5.2 before these steps are taken.
The third sentence is an unnecessary caution which should be
obvious but may cause a lot of confusion. The fourth sentence
starting with "Post..." is something which doesn't work - the signs
are always ignored.
NOTE: The first two sentences are proposed to be moved to section
2.6.1.2 on another proposal form.
COMMITTEE ACTION: Accept.
(Log # 43)
12A- 68 - (B-2.3.3.4): Accept in Principle
SUBMrYIt:R: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Add
"Visually inspect all dampers to ensure they are shut."
SUBSTANTIATION: In practice, dampers presumed to be shut are
often not, due to some failure or othei'. If shut they are often only
~artially shut, misadjusted, broker, or kept open with debris.
ometimes the dampers do not exist or are connected to the wrong
duct. Visual inspecuon is almost always necessary.
COMMITTEE ACTION: Accept in Principle.
Add:
"Confirm that all dampers and closeable openings are in the
discharge mode position.
COMMITTEE STATEMENT: Clarification.
(Log # 67)
12A- 63 - (B-2.2.3.7): Reject
SUBMITTER: R.A. Whiteley, Wormald
RECOMMENDATION: Delete "15%" and Add "5%"
SUBSTANTIATION: A 30 percent error band is unacceptable as it
allows subsequent ELA calculations to be so inaccurate as to be of
little or no value.
Experience has shown 5 percent to be an attainable figure.
COMMrFFEE ACTION: Reject.
COMMI'ITEE STATEMENT: Not consistent with pre-established
calibration requirements.
/
(Log # 41)
12A- 64 - (B-2.3.1.3): Accept
SUBM1TTER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Add:
"number or name each doorway."
SUBSTANTIATION: In order to make repeatable measurements on
these rooms the identical setup vis avis door openings must be
duplicated in future when the door fan test is repeated. I have
proposed adding a step in 9.5.2 and 9.6 where the open or closed
state of each doorway will be recorded. The proposed numbering or
naming will facilitate repeatable retesting.
COMMrrTF~. ACTION: Accept.
(Log # 44)
12A- 69 - (15-2.3.3.5): Accept
SUBMITrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Delete this entire section.
SUBSTANTIATION: The first sentence is covered in the propo~sed
15-2.3.3.3. The balance of this section is proposed to be movedto
2.6.1:2 since these steps would not allow the statis pressure in B-2.5.2
to be measured correctly and apply to door from measurement
procedure only.
COMMITTEE ACTION: Accept.
.
(Log # 108)
12A- 70 - (B-2.3.3.5):Accept
S U B M I T r E R : James M. Rucci, Harrington Group, Inc.
RECOMMENDATION:
Add the following caution statement
following the lastsentenceof the paragraph.
C A U T I O N : The removal of raisedfloor ules creates a serious safety
hazard. Appropriate precautions shallbe taken.
(Log # 106)
12A- 65 - (B-2.3.2.1): Accept in Principle
SUBMITTER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Add the following sentence:
"Calculate the minimum net volume" (gross volume of the hazard
minus the volume occupied by solid objects) of the enclosure."
573
NFPA 12A -- A92 TCR
SUBSTANTIATION: The text currently does not provide a warning
concerning the serious safety hazard which is created when raised
floor tiles are removed.
COIVIMFIT~ ACTION: Accept.
SUBSTANTIATION: We do not often find significant mechanically
induced static pressure. Where this does occur it ma 7 arise either
from insufficiently tight dampers to the airconditionmg within the
enclosure or external alrconditioningin adjoining areas. In the
former instance the dampers shouldbe adjusted to give correct
closure. In the latter instance a static pressure across one particular
enclosing element as measured would not necessarily be the same as
static pressures measured across other enclosing elements.
Further, as the mechanism for halon leakage is assumed to be
leakage out from lower holes and leakage in through top holes it
couldbe argued that the effects of static pressure will tend to cancel
out. Obviously the situation is very complex depending on where the
holes are and where and what the static pressure to all adjoining areas
are. In the light of this we would not support the routine static
pressure compensation method proposed. Rather we feel that w
warning about the influence, of static pressure be "ven in the
standard so that an experienced operator can m a ~ a judgment in
the occasional cases where such problems may be encountered. This
will then permit a multipoint measurement technique to be adopted
which we would suggest is done in the pressurised mode, being more
representative of discharge conditions (unless specific cases preclude
this).
COMMITrEE ACTION: Reject.
COMMZITI~£ STATEMENT: No text provided by the submitter.
(LOg # 45)
12A- 71 - (B-2.4.2): Accept in Principle
SUBMITTER: Colin Genge, Sheltmr Scientific, Ltd.
RECOMMENDATION: Change "area" to "zone."
SUBSTANTIATION: This will match the new proposed definition
for relief zone. Area used here could be confused with leakage area.
I COMMITFEE AG'rION: Accept in Principle.
Change "Relief Area (the largest.., space) to "Return Path Space."
COM]VItI-I~E STATEMENT: Clarification.
(Log # 79)
12A- 72 - (13-2.4.4): Accept in Principle
SUBMITTER: •David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Replace Section B-2.4.4 with:
"13-2.4.4 Examine the sealing around the door (before door fan
installation or after its removal) that the door fan will be mounted in
to determine if substantial leakage exigts. If leaks are found then
their area must be estimated and added to the door fan estimate. If
the door fan has a leaky sealing system, then the door fan leaks must
be subtracted from the total leakage."
SUBSTANTIATION: The current wording would require us to cut
holes in the door seal that.we have worked-very hard'topeffectl It
seems more reasonable to inspect the door seal before door fan
installation or after its removal in order to estimate the door leakage,
and add this leakage to the door fan measurement in order'to get the
total enclosure lea~ge. For small enclosures with a single door, this
can be a major effect.
COMMITTEE ACTION: Accept in Principle.
Replace 13-2.4.4 with the following:
"B-2.4.4 Examine the sealing around the door (before door fan
installation) that the door fan will be mounted in to determine if
significant leakage exists. If significant leaks are found they should be
corrected. If the manufacturers stated door fan sealing system
leakage is less than the apparent remaining leakage of the doorway,
the difference must be added to the leakage calculated in section I32.6 (see 13-2.6.3.5)."
C O M M I T T E E STATEMENT: Clarification.
(Log # 109)
12A- 75 - (B-2.5.2.1): Accept in Principle
SUBMITrER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Add the following after the first sentence:
"Assure that all doors that connect the areas outside the enclosure
envelope are in their normal positions (intended at the time of halon
system discharge)".
SUBSTANTIATION: Stadc pressure measurements should be taken
with doors in the immediate area of the enclosure envelope in their
normal (at discharge) position since opening of these doors to
establish proper relief area may alter tile stauc pressure. The text
currently does not make this clear and implies by sequence that these
measurements should be taken after the relief area is established.
COMMITTEE ACTION: Accept in Principle.
COMMITrEE STATEMENT: Refer to acuon on Proposal 12A-67
(Log #42).
/
(Log # 47)
12A-76- (B-2.5.2.2): Accept in Principle
SUBMITrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Delete the existing section and replace it
with:
"Under pre-halon discharge conditions, measure the worst case
(greatest) pressure differential across a section of envelope containhag the largest quantity of leaks expected to leak halon. If the
subfloor is pressurized at discharge, measure the differential between
the subfloor and outside the envelope. Call this value P~Ta (for static
at halon discharge). Determine the flow direction with ~Moke."
SUBSTANTIATION: The section has been rewritten for clarity and
to emphasize how the room must be specifically set up for this
measurement. The concept of measuring the worst case (greatest)
static and over what wall i f more'than one static exists is introduced
since field experience has shown this to be an issue. The comment
on 1/2 Pa doesn't apply to P g ~ as much as P~'r (where its effect is
nullified with positive and ne'~akive testing.) The original sentence
containing the words "1/9 Pa" is therefore redundant.
C O M M r r r E E ACTION: Accept in Principle.
The submitter s recommendation is acceptable with the following
additions:
1. Add (P~ta) after the first "differential"
2. At the ~vdtlof the recommended paragraph add %. or other
indicating method."
COMMIIIz:E STATEMENT: Clarification.
(LOg # 46)
12A. 73 - (13-2.5,13-9.6 and B-2.7): Accept
SUBMITTER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Change "P wherever it appears to either
Psr" (for test) or "Pro (for halon). '
•
o
Below is a list indicating each location of P, and what it should be
changed to:
Location Change Ps to:
B-2.5.2.2 P .
B-2.6.1.4, a~er "static pressure" add "(P..)"
B-2.6.1.6, after "static pressure add "(PsTI"
13-2.6.1.9 PST
15-2.5.2.3 PSH
B-2.7.1.5 Psr
B-2.7.1.7 P _
B-2.7.3.2 ( ~ PsH
B-2.7.3.2 (e) PsT
B-2.7.3.4.2 ( d ) P m
B-2.7.3.5.2 (d) Ps.
SUBSTANTIATION: These two variables are sometimes the same
but can often differ. They are measured in different ways. To help
differentiae their respective measurement techniques, different
values and significance, they should have different labels.
COMMITTEE ACTION: Accept.
(Log # 110)
12A- 77 - (13-9.5.2.2): Accept in Principle
SUBM1TrER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Revise the first sentence of the text to read
as follows:
"Use a smoke pencil or other indicating method at any fan
apparatus opening to veri~ flow direction and the existence of a
definite pressure differenual."
12A- 74 - (B-2.5.2): Reject
"
"
(Log # 7)
SUBM1TI'ER: Boman Mama, Department of Transport
RECOMMENDATION: Add a warning about the influence of static
pressure and make section 13-2.5.2 on static pressure measurement
optional. '
574
NFPA 12A m A92 TCR
\
SUBSTANTIATION: The text currently suggests that a smoke pencil
be used 0nly i f a pressure is detected on the differential pressure
gauge. This check should be performed regardless of the gauge "
reading as it provides a cross check of the reading and the measured
flows recorded during pressurization and depressurization.
COMMITTEE ACTION: Accept in Principle.
COM]VUTIJ~g STATEMENT: Refer to action in Proposal 12A-84
(Log #50).
(Log # 48)
12A- 78 - (B-2.5.9.3): Accept in Principle
SUBMrrTER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Change the existing text to:
"If'the static pressure (Pq~) is negative a n d h a s an absolute value
greater than 25 percent o'f'the column pressure calculated in 132.6.1.3 it must be permanendy reduced. Static pressures of all
magnitudes and of both directions must be permanently reduced
wherever possible.
Large static pressures a n d large negative pressures in particular
decrease thelevel of certainty inherent in this procedure."
SUBSTANTIATION: This section has been re-written to be more
instructional. Advice is added, to reduce static pressures which in
general are not consistent with good halon retention engineering
and can have unpredictable results. The original text gives the
•
impression large-positive statics are ok- this i-s not so. -COMMITI'EE ACTION: Accept in Principle.
Replace 13-2.5.2.3 with the following:
"If the static pressure (Pq~) has an absolute valuegreater than 25
percent of the column pr~k~ure calculated in B-2.6.I.3 it must be
permanently reduced. I.arge static pressures decrease the level of
certainty inherent in this procedure. The most common causes of
excessive static pressure are leaky dampers, ducts and failure to shut
down air handling equipment serving the enclosure." COMMI'I'I'/~E STATEMENT:
(Log # 111)
1RA- 81 - (B-2.5.2.4 (New)): Accept in Principle
8UBMITTER: James M. Rucci, Harrington Group, Inc.
.
RECOMMENDATION: Add the following new paragraph and note:
."B-2.5.2.4 If the static pressure ( P ) i s positive and has a value
greater than 10 percent of the coluYnn pressure calculated in 132.6.1.4, this procedure cannot be relied upon, and the enclosure mat
not hold the specified halon concentration unless the source of this
excessive static pressure can be identified and permanently reduced.
NOTE: The operating modes of the area I-WAG systems must be
well understood ~and static pressure measurements recorded
under the worst case conditions."
SUBSTANTIATION: The test currently does not provide an upper
limit on the static pressure, measurement
p o s i t i v if
e.
. Due to the fact
that research data addressing stauc pressure measurement effect on
retention is limited, a conservative upper limit is appropriate.
Varying operating modes of building air handling systems can have a
dramatic influence on static pressure measurements. As an example,
m o d e m HVAC design may incorporate night and weekend setback
operating modes where on or more major air handling units are shut
down. Static pressure measurements taken during these periods
would likely hot be worst case.
COMMrITEE ACTION: Accept in Principle.
COMMITTEE STATEMENT: Refer to acuon in Proposal 12.4.-78
(Log #48).
(Log # 16)
12A- 82 - (B-2.6 and B-2.7): Reject
SUBMITTER: William Eckholm, FSSA
RECOMMENDATION: Change present "metric only" system to
English system with metric eqmvalents in parenthesis.
SUBSTANTIATION: To argue with system of units in the rest of the
standard and in all other NFPA standards.
COMM1TI'EE ACTION: Reject.
C O M M I t - I ~ STATEMENT: No text provided.
Clarification.
(Log # 88)
12A- 79 - (B-2.5.2.3): Accept in Principle
SUBMITTER: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Replace SectionB-2.5.9.3 (partial text
change available) to:
"13-2.5.2.3 If the magnitude of the static pressure is greater than 1 Pa
(0.004" we) then this procedure can not be relied on. This applies to
ne ga.tive static, pressures .
Negauve stauc pressures should be treated as if theywere caused by a
leak on the lower surface of the enclosure. If the magnitude of the
pressure is highter, then the enclosure may not hold the specified
haion concentration unless the source of this excessive static pressure
can be identified and per/nanenfly reduced."
Other related sections may have to be modified to reflect this
change.
,
SUBSTANTIATION: Testing and discharging with significant static
should be discouraged because of problems in leakage calculations,
inability to guarantee that the staticpressure will be the same across
all enclosure surfaces, and the potential for variations in HVAC
operating modes which are often the causeof static pressures. Note
that the current procedure allows the test to proceed for any positive
static pressure, no matter how large. Negativ-e static pressures-are
ignored if they are below 25 percent of the column pressure which
ignores the possibility that they may be caused by leaks on the bottom
of the enclosure.
COMMITTEE AGTION: Accept in Principle.
C O M M r Y r ~ STATEMENT: Refer to acuon in Proposal 12A-78
(Log #48).
(Log # 49)
12A-80. (B-2.5.2.4 (New) and B-£.3.1.3): Accept
SUBMn'TER: Colin Genge, Sheltalr Scientific, Ltd.
RECOMMENDATION: Add the following new pal'agraph:
"Record theposition of all doorways, whether open or shut, when
the static pressure ( P ~ ) was measured."
SUBSTANTIATION.~"rhis must be included to ensure a repeatable
condition when the room is retested in future.
COMMITI'EE AGTION: Accept.
(Log # 9)
12A:83 - (B-2.6.1 and B-2.6.2): Reject
SUBMrrYER: Boman Mama, Department of Transport
RECOMMENDATION: Reconsider these sections using multipoint
measurements rather than single point measurements.
SUBSTANTIATION: We do not accept the arguments in favor of
isngle point measurement and consider it in~portant that a full
pressure/flow profile, be. derived for the enclosure using multip.oint
measurement. Thts will allow the value o f N and C to be determined
by test giving a more accurate leakage area determination ~nd
permitting greater flexibility in both measurement and use of the
results.
The new appendix B of NFPA 12A was derived from the report
entitled "Enclosure Integrity Procedure for Halon 1301 Total
Floodin..g Fire Suppression. Systems. Section 4-1.5 of this report offers
.lUSnflcauon for single point flow measurements. In response to the
statements made in Section 4-1.5 we would comment as follows:
4-1.5.3 (a) If this occurs it is due to improper operator procedure.
There is no reason why the n u m b e r and range of points should not
be specified.
,
(b) Such conditions will adversely affect a single pressure reading
more than multipoint readings.
(c) Minor inaccuracies in single point measurement would be more
likely to result in erroneous leakage area in determination than
would be the case in multipoint measurement.
4-1.5.4 (a) This statement is not true. Any individual measurement
is just as simple and just as prone to a gross mistake. Linear
regression analysis of multiple readings will minimize the influence of
any such errors.
(b) & (c) It is more precise to determine N by test.
(d) We would argue against taking pressurlsation and
depressurisation readings.
(e) It is airflow rather than pressure that raises dust. GGJd operator
technique should avoid this. We have not found a significant dust
problem in j3ractice. It would not be necessary to reach 50 Pa where
flow power Is limited. When there is a problem with flow power
multiple fan units should be used.
"(f) The difference in time between single and multipoint measurement is trivial, perhaps 5 minutes.
(g) We do encounter occasions where there are wind effects.
(h) We seldom encounter significant static pressures. Where this
does occur multipoint tests would minimize such effects
COMMFFFEEACTION: Reject.'
COMMITTEE STATEMENT: Refer to action in Proposal 12A-106
(Log #68).
575
/
NFPA 12A -- A92 TCR
The committee is unable to accept this submission on the basis that
t h e p r e s e n t methodology is not adaptable to a close fit calculation
method. As well the submission is insufficient in addressing the other
procedural changes that would be required as a consequence of
accepting this comment.
COMMII-It~E ACTION: Accept in Pnnciple.
Replace B-£.6.1.2 with the following:.
(A) Block open all doorways around the enclosure and post
personnel .to ensure they stay open.
(B) Ensure adequate r e t u r n p a t h area is provided to allow an
unrestricted return airflow path back to the door fan from enclosure
leaks.
(C) Remove I percent of the floor tiles (for false floors) if an '
equivalent area is not already open.
03) If halon is designed tO discharge above the false ceiling, remove
I percent of the ceiling tiles.
(E) Remeasure the static pressure (PsT) at the time of the door fan
test, between the room (not below thefalse floor) and the return
path space.
(Log # 50)
12A- 84 - (B-2.6.1.9): Accept in Principle
SUBMITTER: Colin Genge, Sheltair Scientific;Ltd.
RECOMMENDATION: Revise the existing text to:
"1. Block open all doorways around the enclosure and post
personnel to ensure they stay open.
9. Ensure adequate relief area is provided to allow an unrestricted
return airflow path back to the door fan from enclosure leaks.
3. Remove I percent of the floor tiles (for false floors) if an
equivalent area is not already open.
4. If halon is to be discharge above the false ceiling, remove 1
percent of the ceilin g.tiles .
.
5. Remeasure the static pressure (PsT) at the tame of the door fan
test, between the room (not below the- false floor) and outside.
6. Make every effort to reduce.the static pressure (PsT) by shuting
down air handling equipment even though itmay operate during
discharge.
7. Record P¢'r and its direction (using smoke).
8. Record ti~'e'position of each doorway, open/shut.
9. If the static pressure fluctuates due to rand, use a wind damping
system incorporating 4-averaging tubes on each side of the buildingto eliminate its effects per CGSB CAN. 149-85 standard.
(F) Make every effort to reduce the static pressure (Prr) by shuting
down air handling equipment even though it may operate during
discharge.
(G) Record PST determine its direction using smoke or other
means.
(H) Record the position of each doorway, open/shut.
(1) If the static pressure fluctuates due to wind, use a wind damping
system incorporating 4-averaging tubes on each side of the building
to eliminate its effects per CAN/CGSB-149:I0-1986 standard may be
used.
) Ira subfloor pressurization airhandler cannot be shut down for
e test and leaks exist in the subfloor. If leaks exist in the subfloor,
these leaks may not be accurately.measured. . Eve 0' attem pit must be
made to reduce subfloor leaks to mslgnificance. During the test as
many floor tiles as possible should be lifted to reduce the amount of
subfloor pressurization. Note that u n d e r such conditions the
Suspended Ceiling Leakage Neutralization Method will be difficult to
conduct due to massive air turbulance in the room.
COMMITI'EE STATEMENT: Clarification.
I0. I r a subfioor pressurization airhandler cannot be shut down for
the test and flit causes a -2 Pa (or greater in magnitude) static
pressure (PsT) due to leaks in the subfloor then these leaks should
either be se-aled permanently or floor tiles lifted such that the static
pressure (PsT) is reduced to a lesser magnitude than -2 Pa."
SUBSTANTIATION: The original fails to clearly delineate the actual
steps required. It. links P and PST inappro
. . .riately
.
without spellin
out exactly how it shoul~ls~ measured wlth~imltauons. Seahng o ~
registers may not be appropriate as a later proposed change outlines
measuring BCLA this way. Advising to repeat B-9.5.2 introduces
many steps that do not apply to B-'2.6 measurements. The,"Not~"
becomes redundant because Pm and PST are clearly separated by the
new proposals,
o
Substantiation by sentence.
1. These doorways should be shut till now.
9. Adequate relief area must be ensured here, prior to door fan
measurements to yield accurate results.
3. This ensures any leakage areas (or statics) will be accurately
measured in later steps.
4. This ensures linkage between the room and any large above
ceilingleaks.
5. The room is now det up to door fan test conditions and is ready
to have its static pressure (Po.) measured.
6. Static pressure reductioh's will increase the accuracy of door fan
leakage area measurements.
7. Record the static pressure (PsT) here since presumably no more
efforts will be made.
8. Door position is important for test repeatability.
9. Fluctuating static pressures due to wind can greatly affect the
accuracy of both the true static pressure and leakage area measurem e n t s . T h i s is rarely a i~roblem since halon facilities are normally
rooms within buildings where wind effects aren't felt, but some are
exposed to the outdoors on all or most of the sides and wind is
capable of creatirig pressures in the same order of magnitude as those
being measured. Door fans are widely used for energy related tests
where the wind issue has been dealt with by using pressure averaging
systems. The wind may create high pressures on one .wall but ove/'ail
this is offset by low pressures on others. When averaged they tend to
net out to near zero. A four tube averaging system is described by the
CGSB procedure whereby one tube goes to each side of the building.
Each tube is damped then manifolded into the pickup point. The
system works well at reducing peak fluctations and yielding more
readable gauges.
10. Large leaks in pressurized floor voids will skew leakage area
measurements- in effect the pressurized floor with attendant leaks
can set to discharge a net quantity of air from the room and thereby
depressurize the above floor space with respect to outside the
enclosure. For example a .195Pa subfloor pressure could create a-5
Pa pressure above the floor - the result would be to measure the ELA
as being25 percent lower than actual. Sealing the leaks is obviously,
preferable but if not possible at least the floor tiles should be lifted to
get away from the inaccuracy caused by the subfloorpressurization
flow. A pressure of-9 Pa was chosen since this shouldcreate an error
of less than 10 percent in the leakage area measurement in most cases.
-
(Log # 8)
19A- 85 - (B-£.6.1.3): Reject
SUBMrlTER: Boman Mama, Department of Transport
RECOMMENDATION: Reconsider this section using the appropriate column pressure rather than a 10 Pa minimumpressure.
SUBSTANTIATION: We note your proposal to refer predicted hold
times to the column pressure involved. We have carried out a small
series of pressure measurements, during discharge tests which
confirms the initial residual pressures assumed wlth the exception of
a particularly leaky enclosure which achieved only about 2/3rds
assumed pressure. We would therefore support the proposal to refer
results to the appropriate column pressure, although we do not
believe the measurements need be taken at this pressure in a
multipoint technique is used. We would have haa occasion to
examine lower height, void-type, enclosures where a lower column
pressure would be appropriate.
From the point of view of the retention time calculation method, we
understand that this reference to the initial column pressure
throughout rather than making any provision for the reduction in
column pressure with time arising from the descent of the interface.
Such a methodology will predict preternamraily short retention times
particularly in high enclosures with low risk heights. The measurements we have made clearly indicate that the column pressure
reduces with time proportionally to descent of the interface. We
would therefore favor this feature being included in the calculation
methodology.
COMMITTEE AGTION: Reject.
COMMITI'EE STATEMENT: No text provided by submitter.
(Log # 51)
12A- 86 - (B-2.6.1.4): Accept
SUBMITTER: Colin Genge, Sheltair Scientifc, Ltd.
RECOMMENDATION: Add "(Psx)" after "static pressure" in 2
PAd
laces.
d "a P of" after the "until" in 9 places.
Replace ~ae first sentence with:
"Depressurize the enclosure with a door fan blower(s) till the
measured pressure differential reading on the gauge (P~) goes
through a total pressure reduction ( d P ) equMto the c t l u m n
pressure (P~)."
=
SUBSTANTIATION: PST and P_ additions should be made to clarify
where they're used appropriately".
576
NFPA 12A - ~ A92 TCR
(Log# 113)
12A- 91 - (B-2.6.1.8 Note (New)): Accept in Principle
SUBMrlTEI~ James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Revise the second sentence of the paragraph
to read as follows:
"Ensure that while pressurizing, the reference side of the flow
pressure gnage(s) reads the ambient pressure outside of the
enclosure if appropriate."
Also, add the following note at the end of the' paragraph:
NOTE: For the case in which test instrumentation is set up on
the exterior of the enclosure, the referencing requirement stated
above applies to depressurization and ambient interior pressure.
SUBSTANTIATION: The referencing requirement is not consistent
between fan apparatus manufacturers. The necessary reference
corrections are-completed either physicMly or mathematically,
depending on the equipment andsoftware being used.
The test as currently written applies to test instruments located
within the enclosure. There are cases in which, due t6 physical
characteristics of the enclosure, the test instruments must be set up
on the exterior. Examples of this would be a very small enclosure or
an enclosure with a long and narrow interior entry. In these cases,.
interior set tip of instruments could result in obstruction to the fan
airflow.
COMMYI'rEE ACTION: Accept in Principle.
COMMrlTEE STATEMENT: Refer to action in Proposal 12A-90
(Log #52).
The first sentence is ambiguous as to whether d P is the gauge
reading or the pressure change. P is included td'tnake sure the
reader can relate to the correctprer~sures in other sections, e.g. in
retention calculations. Other changes are editorial for clarification.
COMMITTEE ACTION: Accept.
(LOg # 87)
1ZA- 87- (B-2.6.1.4): Reject
SUBMrrFER: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Revise B-2.6.1.4 and other sections with
static pressure (text not available):
"Summary. of changes: Target pressure selection would be
simplified if the room pressure gauge was zeroed to the actual room
pressure rather than zero pressure. This would involve changes in a
number of sections."
SUBSTANTIATION: Under the current procedure, the s{atic
reSsure is measured and it is used to compute the target pressures
r pressurization and depressurization. If the gauges were zeroed to
the actual room pressure, then the target pressure would be the same
under pressurization and depressurization. This would simplify t h e
provedure and the calculations and reduce the change for error due
to incorrect sign of the static ~pressure.
COMMITTEE ACTION: Reject.
CO M M r r r ~ STATEMENt: No text provided by submitter.
(Log # 112)
12A- 88 - (B-2.6.1.4): Accept in Principle
SUBMITTER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Add the following prior to the first sentence
of the exisdng text:
"Verify that adequate relief area has been established."
SUBSTANTIATION: Due to the critical nature of the relief area with
respect to accurate measurements, it is appropriate that the text
suggest this check at the point at which these measurements are to be
taken.
COMMITTEE ACTION: Accept in Principle.
COMMII-IJ~E STATEMF.aNT: Refer to action in Proposal 12A-67
(Log #42).
(Log # 53)
12A- 92 - (B-2.6.1.9): Accept
SUBMrFrF,R: Colin Genge, Sheltair Scientific, Ltd.
J RECOMMENDATION: Delete this section entirely.
SUBSTANTIATION: This section was originally written by myself to
allow for the testing of spaces with large HVAC flows in.to or out of
the space such that it would not be possible to both pressurize and
depressurize because of the magnitude of the flow. This has not
come up as a problem. This method was theorized to improve
accuracy when large statics occur. This has been made unnecessary
by the new proposed method in ~2.6.3.5. Finally, it is doubtful
anyone has understood B-2.6.1.9 to apply it anyway.
(Log # 56)
12A- 89 - (B-Z6.1.6 and B-2.6.2.7): Accept in Principle
SUBMITTER: Colin Genge, Sheltair Scmntific, Ltd.
RECOMMENDATION: Change "lower" to "lesser in magnitude."
Add "(dP m)" after "generated."
SUBSTANTIATION: The reader could mistake -8 as being not lower
(i.e., higher) than -10. What is meant here is that this pressure
should not be lesser in numerical value or magnitude. Add dP m to
reinforce its correct usage.
COMMITTEE A CTI,ON: Accept in Principle.
Change "lower to "lower in absolute value".
C O M M r r r E E STATEMFaNT: Improved wording.
(Log# 114)
I~.- 93. (B-2.6.1.9):Accept
SUBMYrTER: James M. Rucci, Harrin~ton Group, Inc.
RECOMMENDATION: Delete the enure paragraph.
SUBSTANTIATION: Research data which addresses the effect of
high positive static pressure conditions is extremely limited with
respect to retention time results. The text implies that any static
pressure value is acceptable as long as the fan apparatus can be u s e d
to measure the forcedainC]ow. Research data can not substantiate
this.
COMMITTEE ACTION: Accept.
12A- 90 - (B-2.6.1.8): Accept in Principle
(Log # 52)
SUB~:
Colin Genge, Sheltair S.cientific, Ltd.
RECOMMENDATION: The second sentence should be rewritten to
I~A- 94 - (B-2.6.1.10 B-2.6.3.3 Note (New) and B-2.7.'3.2 (f) and (g)):
Accept
SUBMITTER: Colin C,enge, Sheltair Scientific, Ltd.
RECOMMENDATION: In B-2.6.1.10 change ~I'F" to *TI" and "TL"
to u r n - .
In 1~2.8.S.3 add the following note:
"NOTE: when depressurizing,
when pressurizing
"It = T o T L = Ti,
T~ = T."T F = T O
In B-2.7.$.2 add "('IT)" to (f) and 'PEn) * to (g).
SUBSTANTIATION.~ The temperatuYe of air [going through the fan
(To) varies from being the temperature of air reside the room ('IT) to
th~temperature of air outside the room (Tn) when depressuring~
and pressurizing respe'ctively. The changes'tell the operators where
they should be used.
COMMITTEE ACTION: Accept.
COMMrlIIEE ACTION: Accept.
(Log # 54)
Sa~he flow pressure reading must always be the differential pressure
between the zone in front of the flow devices inlet and the flow device
so that the measured pressure differential (Pm) does not affect the
flow pressure measurement."
SUBSTANTIATION: The original sentence does not apply when
setting up the door fan from outside the enclosure. The proposed
sentence is more general and would apply to a wider r'ange of
equipment and to all combinations of setup conditions.
COMMITTEE ACTION: Accept in Principle.
Delete second sentence in original B-2.6.L8.
Add to B-2.6.1.5:
•"It is important to ensure manufacture instructions are followed to
ensure that air flow is accurately measured with respect to direction
of flow.."
COMMITTEE STATEMENT: Clarification and text improvement.
(Log # 78)
12A- 95 - (B-2.6.2): Reject
SUBMIT1T.R: David $aum and J o h n Hupman, INFILTEC
577
NFPA 12A -- A92 TCR
COMMITTEE ACTION: Reject.
RECOMMENDATION: Add a new Section after 13-2.6.2 called
Suspended Ceiling Leakage Calculation (text not available):
Summary of new section after 13-2.6.2. "This secdon would describe
a new technique to compute the leakage of the ceiling, leakage above
the ceiling, and the leakage below the ceiling. It involves measuring
the pressure across the suspended ceiling when the ceiling is intact,
,and then measuring the pressure across the ceiling after a hole of
known size is opened u p i n the ceiling. These pressure measurements are used to compute the threeleakage areas."
SUBSTANTIATION: The suspended ceiling neutralizationtechnique that is now in the standard is di~qcult to use because it
requires a second fan, it uses an imprecise qualitative smoke
technique to determine neutralizauon, and there is no controUed
experimental data to indicate its accuracy or limits of performance.
The new caiculation technique requires only one fan, uses a digital
pressure gauge for quantitative results, and the calculations can
estimate the errors. This new technique is now being tested.
COMMrlTEE AGTION: Reject.
COMMITI'EE STATEMENT: No text provided by submitter.
12A-96- (B-2.6.2): Reject '
(Log # 115)
SUBMrFrER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATION: Delete paragraph B-2.6.2and all other text
references concerning ceiling neutralization methods. (B-1.2.2.4, B2.2.1.6, B-2.4.1, B-2.6.3.1, 13-2.6.3.6, B-2.7.1.2, B-2.7.3.1, B-2.7.3.5, ]32.7.3.5.2, and B-2.7.3.6 ail contain direct or indirect references to the
testingmethoti.)
SUBSTANTIATION: The suspended ceiling leakage neutralization
method has numerous inherent problems as implemented. Several
of these are as follows:
1. In reality, this method is generally implemented when the
enclosure envelope being tested can not pass a whole room testing
approach. Therefore, leakage above the suspended sealing is
"
accepted if passing results can be obtained through ceiling neutralization. In theory, a large enclosure could fail a whole room test due to
severe leakage above the suspended ceiling and ]let pass a ceiling
neutralization test. This would ultimately result m no additional
sealing efforts to be undertaken.
By virtue of retaining this testing option, there is no incentive to
ensure proper sealing throughout the enclosure.
2. The method is highly subjective as currently conducted as the
movement of smoke at multiple points on the ceiling is observed.
This movement may vary dramaucally at different locations of the
ceilifig due to turbulence created and other effects. Bracketing of
flow values is necessary at each sample poir/t since there is a range of
flows at which the movement of the smoke is not clearly up or down.
The testing technician must remain mindful of the operaung mode
of the fans and the cohservative direct of the smoke movement. This
can be very confusing if not well understood and therefore, may
result in non-conservative errors.
8. Multiple sampling points on the suspended ceiling must be
investigated to ensure that the ceiling is neutralized. This requires
significant time to complete while enclosure HVAC equipment is shut
down. The problem of enclosure heat-up discourages ~ o r o u g h
investigation to ensure neutralization.
4. Because of the subjectivity of the method, it is unlikely that the
intended accuracy of the procedure could be duplicated by different
testing technicians.
5. Results of this testing method tend to vary greatly between
pressurization and depressurization. This is apparently due to
significant differences-in airflow within the susp-ended ceiling area as
air is blown out of or enters the flexible duct. It is apparent that
additional research data is necessary to validate this method.
6. Enclosure construction may not be readily recognized as
inappropriate for the method. As an example, a masonry enclosure
with raised floor and suspended ceiling may be built with wallboard
on metal studs attached to the masonry wails. Typicaily, the
"
wallboard would extend from raised floor to suspended ceiling only,
creating a void behind the wallboard. Ceiling neutralization testing
could discount the leakage behind the wallboard, resulting in a
nonconservative prediction.
An alternate approach to the problem of accepting leakage above
the suspended ceilingwould be to allow the method to be an option
only if the enclosurehas previous passes a whole room testing
approach. This could allow fine tuning of the retention time_
Acceptance'of this alternate approach is questionable as it is unlikely
that the additional ceiling neutralization testing efforts would be
undertaken for "fine tuning" purposes unless required. Also, it is
apparent that additional/'eseardi into this current technique as well
as the potential for pressure drop measurement across the suspended
ceiling is necessary.
COMMrt-llflg STATEMF, NT: Refer to action in Proposal 12A-97
(Log #55), Proposal 12A-99 (Log #57) and Proposal 12A-100 CLog#93).
CLog # ~5)
12A- 97. (B-2.6.2.1): Accept in Principle
SUBMtt-I~R: Colin Genge, Sheltair Scientific, Ltd.
" •
RECOMMENDATION: Remove the words "and through the
ceiling." from the first sentence.
SUBSTANTIATION: The leakage area through the ceiling is not
and should not be measured.
COMMITTEE ACTION: Accept in Principle.
Add "unobstructed" between "continuous" and "ceiling" in the
second sentence.
Add: This technique may be difficult or impossible to perform
under the following conditions:
(A) Air movement within the room may make it difficult to observe
neutralization, particularly in small rooms.
(B) Obstructions above the suspended ceiling i.e., beams, ducts,
and partitions may make it difficult to obtain uniform neutralization.
(C) Limited clearance above the suspended ceiling e.g. less than
one ft, may make it difficult to obtain neutralization.
COMMHTEE STATEMENT: Clarification.
]
012A- 98 - (13-2.6.2.3 Note (New)): Accept
SUBMrrrER: Technical Committee on Halogenated Fire Extin:
~tl~shing Systems
COMMENDATION: Add:
Note: Temporary sealing of such openings is not permitted when
conducting a Total Enclosure Leakage Test.
SUBSTANTIATION: Clarification.
COMMrITEE ACTION: Accept.
A
(Log # 57)
12A. g9 - (B-2.6.2.4): Accept in Principle
SUBMITrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Add "to neutralize leaks through the ceiling"
after the first word "space."
Add "to measure the no w isolated below ceiling leakage area" to the
end of this section.
SUBSTANTIATION: These two additions will help explain the
functions of the two blowers and to emphasize that the lower blower
does the measuring. This additional explanation is necessary to help
the reader visualize the procedure.
COMMI'ITEE ACTION: Accept in Principle.
Add the following at the end of existingB-9.6.2.4:
"It is not necessary to measure airflow through the upper fan."
COMMITTEE STATEMENT: Clarification.
'
(Log # 9S)
12A- 100 - (B-2.6.2.5): Accept in Principle
SLrBMITrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Change the existirig text to:
"Depressurize above and below the suspended ceiling by adjusting
two separate blowers till the required pressure reduction and
suspended ceiling leak neutralization (i.e., no airflow through the
suspended ceiling) is achieved.
Leaks are neutralization when at opened locations in the suspended
ceiling.a neutral.
. density.smoke does not. move up or down. . I f
neutrahzauon ts not posstble at all locanons, ensure etther smoke
does not move or moves down (but not up). Choose undisturbed
locations away from flex duct flows, airstreams and lighting fixtures
because local air velocities make neutralization difficult to-detect.
SUBSTANTIATION: Mostly the original has been rewritten for
clarity but often it is not possible to neutralize all leaks - some will leak
up and some dowm. In this case the proposed procedure allows for
an approach where the extra flow required can be measured yielding
a conservative guarantee of maximum below ceiling leakage area
measurement. New section is more specific.
GOMMITrF~ ACTION: Accept in Principle.
Replace B-~.6.2.5 with the following:
578
NFPA 12A -- A92 TCR
~Depressurize above and below the suspended ceiling b)) adjusting
two separate blowers fill the required pressure reduction a n d
suspended ceiling leak neutralization (i.e., n o airflow through the
suspended ceiling) is achieved.
Leaks are neutralized when at o p e n e d locations in the suspdnded "
ceiling smoke does n o t moye up or down when emitted within 1/4 in.
of the openings. If neutralization is not possible at all locations,
ensure either smoke does n o t move or moves down (but not up).
Choose undisturbed locations away from flex duct flows, airstreams
and lighting fixtures because local air velocities make neutralization
difficult to detect."
COMMITTEE STATEMENT: Clarification.
depressurization and +5+10 = +15 Pa for pressurization. To depressurize to -5 Pa the total airflow required out o f the space will be:
Q = 5 X 1.0/1.271 = 1.76 mS/see.
For the door fa~ to achieve a P,, of-5 Pa (or dP m o f 10) it must first
blow out 1.76 m [sec to neEate ihe flow causing the +5 Pa static
pressure then blow an addiuonai 1.76 mS/see to establish -5 Pa. The
door fan will therefore measure an airflow o f 1.76 + 1.76 = 3.52 mS/
sec in the depressurize mode.
To next pressurize to +15 Pa the total airflow into the space must be:
Q = 15 X 1.0/1.271 = 8.05 mS/see
For the door fan to increase the pressure from the static of+5 Pa to
+15 Pa it must blow 3.05 mS/see, less the flow supplied by the HVAC
supply register flow of 1.76 mS/see. The door fan will therefore
measure an airflow o f 3.05-1.76 = 1.29 mS/see in the.pressurization
mode.
Using the old m e t h o d to calculate leakage area, we get:
Depressurization: A = 1.271 X 3.52/10 "5= 1.415 m s
Pressurization: A = 1.271 X 1.29/10 s = .518 m s
average = 0.967 m s
Using the proposed m e t h o d we get:
Depressunzauon: A = 1.271 X 3.52/ (-5 / 5 = 5 / 5)
= 1 . 2 7 1 X 3 . 5 2 / (5+ 5 = 1 . 0 0 m s
Pressurization: A = 1.271 X 1.29/ 15 / 15 = 5 / 5)
= 1 . 2 7 1 X 1.29/ (15 --" 5 = 1 . 0 0 m s
average - 1.00 m s
1 U ~ ' I 0 1 - (B-216.2.8):Accept
(LOg# 94)
MITTER: Colin Genge, Stieltair Scientific, Ltd.
RECOMMENDATION: Add to the e n d o f existing sentence:
" . . . except, either smoke does n o t move or moves up (but not
down.)
S U B S T A N T I A T I O N : To conform to the proposed changes to B2.6.2.5.
COMMITTEE ACTION: Accept.
What has been accomplished in the new proposed m e t h o d is to
effectively add up the flows to yield the net measured flow wimessed
by the door fan. The math was changed around for simplicity
resulting in a sum o f the square roots of the pressure changes with
their directions taken care of by some awkward looking but simple to
use math.
• This new assumption o f the pressures not being additive is n o t
always true but errs on the side o f safety. The old procedure yields
very small errors at low static pressures but m u c h larger errors at
larger statics. This is demonstrated by the following table:
dP
P-error
10 m 5~L 3.4%
~-
(Log # 59)
12A- 102 - (13-2.6.2.9 (New)): Accept
SUBM1TTER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Add new text:
"B-2.6.2.9 A second m e t h o d for measuring the below ceiling leaks
would be to temporarily seal all ceiling ducts, holes and registers and
to then remeasure the BCLA with one door fan to obtain a beloW,
ceiling leakage area measurement. No flex duct would be used. This
m e t h o d would apply where large ceiling level leaks existed but no
suspended ceiling."
SUBSTANTIATION: Large ducts often enter the top o f an enclosure
and d o n ' t allow for halon leakage but do provide a large leak to the
door fan and an overly conservatlve,result. These may no other way
to measure the BCLA i f a fake ceil!ng d o e s n ' t exist and this makes no
sense.
C O ~ ' l - l ' ] t t £ ACTION: Accept.
10
10
29.3%
15
56.3%
Using difference measured pressure changed ( d P ~ ) within the
allowed 30 percent range for the depressunzation ~!~d pressurization
cases can magnify the-above errors many times.
For any given set of measurements the proposed m e t h o d will always
yield a larger measured ELA (and hence a shorter calculated
retention time when static pressures are present.
C O M M I I - r ~ ACTION: Accept in Principle.
Change equation (3) to:
A = (1.271)(Qc)/(Pro/ P m "PsT/ Ps'r ) +AD
Add " P.~ = square root of the absol-fitevalue of pm
Psv = square root of the absolutevalue of Po.
A n = area of door leakage minus area of d0or~an sealingsystem
Icaltage.
C O M M I T T E E S T A T E M E N T : Additions are to accomodate changes
required by Proposal 12A-72 (Log #79).
/
(Log # 60)
12A- 103. (B-2.6.3.5i: Accept
S U B M t T r ~ q : Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Delete "(door fan)".
SUBSTANTIATION: The 0.61 has nothing to do with a door fan but
a lot to do with a flat plate. This coefficient is however, a c o m m o n
way o f representing door fan results but should not be linked
specifically to door fans.
'
COMMITI'EE ACTION: Accept.
(Log # 118)
12A- 105 - (B-2.6.3.5): Accept
SUBMrI'TER: James M. Rucci, Harrington Group, Inc.
RECOMMENDATIOI~ Revise the text to read as follows:
"A=Areaofleaks (m)
SUBSTANTIATION: Editorial change - units currently shown as m 3.
COMMITTEE ACTION: Accept.
(Log # 61)
12A- 104 - (B-2.6.3.5): Accept in Principle
SUBMITTER: Colin C,enge, Sheltair Scientific, Ltd.
RECOMMENDATION: Change equation (3) to:
NSERT ARTWORK T H R O U G H O U T #61 A = (1.271) (Qc)/(Pro / Pm
" PST /
P~T )
A~id"' " "Pro = square root o f the absolute value of P m
PaT = square root o f the absolute value o f P°~"
SUBSTANTIATION: The p r o b l e m with the e'~isting section is that
the use o f d P ~ in the equauon (3) assumes pressures are directly
additive whidi they nrobablv are •n o t " dP r a is the pressure
change
.
.
caused by the door [an and Is a m v e d at by numerically adding the
static pressure to the pressure measured on the gauge. I f a static
pressure (PsT) is caused by leaky HVAC ducts blowing air into the
enclosure for example (at the ume o f the door fan test), then the
correct leakage area will only be measured when this airflow and the
door fan measured flows are correctly accounted for with respect to
their contribution towards the observed pressures. The situauon can
best be understood by following through the following example.
Example.
A room with a 1 sw meter leakage area has a +5 Pa static pressure
(PsT.) caused by an HVAC supply register flow. The flow rate
r e ~ i r e d to cause the pressure can be calculated from: Q = DP X A /
1.~)71.
10
(Log # 68)
12A- 106 - (B-2.7): Reject
SUBMITTER: R. A. Whiteley, Wormald
RECOMMENDATION: Rewse 13-2.7 with the following:
"Calculation Procedure
The fan test results can be presented in the form:
~q~e rePx
Q = Air lead rate (M3/s)
P = Room pressure (Pa)
C = Intercept at I Pa
N = Slope o f graph line"
Revise B-2.7.1 with "Determine the values o f C & N"
Revise B-2.7.2 with the following:
•
"Determine the density of the H a l o n / a i r mixture (fro) using:
rm = 6.38 X c + ra (100 - c)
100
100
•
Therefore, Q = 5 X 1.0/1.271 = 1.76 mS/see
If Pc = 10 the m i n i m u m target pressures will be +5+5-10 = -5 Pa for
579
NFPA 12A -- A92 TCR
where
c = Halon concenwation
rm = Halon/alr mixture densi~ (kg/M s)
ra = Air density (1.202 k g / M s)
Revise B-2.7.3 with the following:
"Determine the Halon/alr column pressure (Pro)
from P m = G X Ho X (rm - ra)
Pm = Halon/air column pressure (Pa)
G = gravitational constant (9.81m/sec ~)
Ho = Height of protected enclosure (M)"
Revise B-2.7.4 with the following:
"Calculate flow of Halon/alr mvcture from enclosure (Qum) using
(Log # 62)
12A- 107 - (B-2.7.1.3): Accept
SUBMtx-r~..;Pa Colin Genge, Sheltair Scientific, Ltd.
. RECOMMENDATION: Add the followin~g formula to (7):
"ifFA is greater than 0.50 make Fa=0.50
SUB~'I'ASTIATION: Section B-1.~3.7 does not allow for 2-way (bidirectional) leaks. When FA becomes greater than 0.5 bi-directional
flow starts to occur.
If the BCLA is mistakenly measured as being very lar~[e due to leaky
ceilin~ ducts or whatever the result will yield an excessively long
retenuon time. If BCLA = ELA the formula divides by zero.
COMMITTEE ACTION: Accept.
~QUvi
m
= Uncorrected
CPm ~
m ffi
flow of Halon/alr mixture (MS/s)
se B-2.7.5 with the following:
"Correct flow of Halon/alr mixture for temperature (Qcm) using
Qcm = Qum TL+273
TF+273
TL = Temp of air passing through leaks (°C)
"IT = Temp of air passing through fan (°C)"
Revise B-2.7.6 with the following:
"Calculate equivalent leakage area (ELA) using
ELA = 1.271 Qcm
pm0.S
• ELA = Equivalent leak~age area (M~) ~
Revise B-2.7.7 with the following:
"Calculate the total leakage area (At) from
At= K X E L A
• K = Leak orifice coefficient (0.61 to 1.0)"
Revise B-2.7.8 with the following:
"Determine leakage fraction (Fa) from
Fa = All
At
All = Area of lower leaks"
Revise B-2.7.9 with the following:
"Determine hei,,ght in meters at which Halon concentration is to be
maintained (H)
Revise B-2.7.10 with the following:
"Calculate constants C s and C4 as follows:
Cs = 2G (rm - ra)
ra (rm + Fa)1N
(Log# 71)
12A- 108 - (B-2.7.1.3): Reject
SUBMrrlT.,R: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Revise B-2.7.1.3 by inserting the sentence:
"A,r must be measured with the suspended ceiling open'."
Siffiilar changes must be made to the sections that describe howto
measure the total leakage area. Note that this applies to section ~2.6.2.3 where it is not clear if the sealing can be used when the total
leakage is measured. B-2.6.1.2 might need revising to prevent sealing
of vents that appear to be registers, but actually go into the plenum.
B-2.3.3.5 may need revising since it explicitly states that ceihng tiles
not be removed.
SUBSTANTIATION: If the ceiling is tightened, then the total
leakage gets smaller, and the leakage ratio in equation 7 gets larger.
This makes the hold time longer.
But if halon is discharged and a ceiling tile is blown out (a common
occurrence) then the total leakage is not larger and the actual hold
time is shorter. Unless the ceiling is guaranteed not to blow a tile on
discharge, then all total room leakage measurements should be done
with ceiling tiles removed.
COMMrrI'EE ACTION: Reject.
COMMITTEE STATEMENT: The procedure (B-1.2.3.10) assumes
all halon discharge !s totally within the halon protected enclosure i.e.,
ceiling tiles remmn m tact.
(1-Fa)
C 4 = 2 Pm
rlYl"
Revise B-2.7.11 with the following:
"Calculate the time (t) in seconds for Halon concentration to fall to
height (H) using
t = V (C s Ho + C4)1"~¢(CsH+C4)1"~¢
Ho
(l-N) (Cq FaAt)."
SUBSTANTIATION: The existing calculation procedure is inaccawate
and does not always give conservauve predictions. Practical instances
occur when actual hold times have been significantly less than the
predicted hold time. The proposed calculation method gives consistanfly
more accurate predictions Whilst being conservative.
Multi point pressure/flow readings are required to determine C &
n. Pressure readings should be amended by the residual static
pressure recorded. This overcomes:
(a) The potential error in taking only one, low pressure reading.
(b) The t'act that different enclosures have different leakage
characteristics, i.e., differing 'n' & 'C' values.
(c) The inaccuracy of using an exponent of 0.5 instead of the actual
'n' value of the enclosure leaks.
The proposed procedure still compensates for static pressure.
Halon mixture density is calculated as before
Halon column pressure calculated as before.
It is necessary to determine the rate at which Halon leaks under the
Halon column pressure, rather than just air i.e., what actuary
happens after Halon discharge. Therefore use Qum = cPm .
Correct the flow Qum for temperature as before, and calculate
Halon mixture ELA using CGSB Formula.
This procedure compensates for the different leak rate of Halon
compared with air thereby giving a more accurate result.
Complete calculation of At, Fa, H and t as before.
NOTE: "Supporting material is available for review at NFPA
Headquarters."
C O M M I T T ~ ACTION: Reject.
"COMMrlTEE STATEMENT: "Refer to action in .Proposal 12A~3 (Log #9).
The committee is unable to accept this submissmn on the basis that
the present methodology is not adaptable to a close fit calculation
method. As well the submission is insufficient in addressing the other
procedural changes that would be required as a consequence of
accepting this comment.
(Log # 10)
12A- 109 - (B-2.7.1.6): Reject
SUBMITIt~R: Boman Mama, Department of Transport
RECOMMENDATION: Reconsider the concepts used for determining acceptance currently based on minimum height.
SUBSTANTIATION: We are concerned that the predictive method
proposed assumes failure to be when the concentration reaches half
the ~nitial value at a specified height. Although under sharp interface
assumptions this would be satisfactory, under the usual wide interface
situateion this would mean that a retention time for 2.5 percent
concentration is applied for 5 percent design systems. As for certain ~
materials this concentration isbelow the extinguishing concentration
we consider it an unsound criteria to be adopted. We would prefer
the current UK practice to predict for 80 percent of nominal
standard design concentrauon (i.e., 4 percent for a 5 percent system
regardless of whether the actual halon quantity wouldexceed 5
percent.) This criterion would ensure that the extinguishing
con'centration is maintained for all material risks present. It also
ensures that there is no penalty applied if an installer puts in more
halon than the standard actually requires.
We also feel that some guidance needs to be ~iven to the authorities
having jurisdiction as to what height the retenuon time should be
predicted for. It is not unusual for us to be asked by an authority
without knowledge of halon to predict for 5 percent at ceiling level;
obviously an untenable requirement. We would'suggest that the
height of the highest item requiring halon protection is recommended with examples as to what this might comprise. Similarly
some guidance could usefully be given on the acceptability of the
hold lame predicted (10 minutes unless otherwise specified.)
COMMITTEE ACTION: Reject.
COMMITTEE STATEMENT: No text provided by submitter.
(Log # 95)
12A- 110 - (B-2.7.1.6): Accept in Principle
SUBMrrFER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Add to existing text"
"If continuous mechanical mixing occurs during the retention time
"such that a descending interface does not form and the halon
concentration is constant throughout the protected enclosure,
calculate an effective m i n i m u m h e i g h t based on the initial and final
580
NFPA 12A -- A92 TCR
ecified concentrations. Example: H - 4m, initial concentration =
, final = 5%, effective minimum height = 5/7 X 4m = 2.88m.
Ensure mixing is not created by ductwork which leaks excessively to
zones outside the enclosure."
.
SUBSTANTIATION: Since many enclosures have mechanical
mixing, excluding them from the procedure vastly reduces the
usefulness of appendix B. The procedure outlined is conservative to
the extent that as time goes on the halon gets lost at an ever
decreasing concentration. This error is about 15 percent for the
example shown. This is not critical but a closed form solution to the
differential equation would be more accurate but less conservative.
COMMITTEE ACTION: Accept in Principle.
Add to existing text:
"If continuous mechanical mixing occurs during the retention time
such that a descending interface does not form and the halon "
concentration is constant throughout the protected enclosure,
calculate an assumed value for H based on the initial and final
specified concentrations using' the following equation:
H = c x Ho
c,
(9)
where:
H = Assumed value for H for mixing calculation ~,
c = Actual Halon 1301 concentration ( % )
J
Cr = Final Halon concentration per authority having jurisdiction
requirement.
H o = Maximum Halon Protected Height
Example: H o = 4m, initial concentration = 7%, final = 5%, H = 5/7
X 4m = 2.88m. Ensure mixing is not created by ductwork which leaks
excessively to zones outside the enclosure."
COMMITTEE STATEMENT: Clarification.
(Log # 17)
lEA- 111 - (B-2.7.1.7): Reject
SUBMITFER: William Eckholm, FSSA
RECOMMENDATION: Revise to read:
~rime. Calculate the minimum time that the enclosure is expectecl
to maintain the descending interface above (H) at both the design
concentration and at 80 percent of the design concentration, using
the following equations ..."
SUBSTANTIATION: When conducting a discharge test per
paragraph A1-7.4, acceptance requires that 80 percent of the design
concentration shall be held for 10 minutes. As presently worded, the
door fan test requires that the concentration at (H) be at 100 percent
of the design concentration. The revised wording will allow the door
fan test to consider the effects of a synthetic reduced leakage rate
(due to less head at 80 percent concentration), and more closely
compare to criteria if in fact a discharge test was conducted.
COMMITTEE ACTION: Reject.
COMMITTEE STATEMENT: The calculation method calculates for
time. The user can increase the required holding time and therefore
achieve the 80 percent interface criteria.
(Log # 63)
12A. 112 - (B-2.7.1.7): 'Accept
SUBM1TrER: Colin Genge, Sheltair Scientific, Ltd.
,RECOMMENDATION: Revise the following:
"Equation (9): change " I / N to "2". This corresponds to an N or 0.5.
Equation (11): change "(l-N)" in 3 locations to "0.5." .
Delete N = Exponent value (0.5)."
SUB,STANTIATION: I have tried calculations using N and they
don e work. For one thing ifN is other than 0.5 it must be specified
at a certain pressure (where measured) and no provision exists for
that but more simply N ranges from 0.5 to 1.0. IfN=l is substituted in
(11) the division becomes 0 and the time infinite which is clearly
wrong. The N values for these rooms are normally very close to 0.5
an) way. Using N values aren't consistent with the rest of the method.
COMMITTEE ACTION:.Accept.
(Log # 74)
12A- 113 - (B-2.7.1.7): Accept in Principle
SUBMITFER: David Saum and John Hupman, INFILTEC
RECOMMENDATION: Revise Section B-2.7.1.7 Time. (revised text
not available)
"Summary of Revisions: Equations 9, 10, and 11 may have 'an error
due to an assumption about the nature of static pressure in halon
enclosures. They may have to be revised or the static pressure
compensation might be eliminated.
If this matter is not resolved, add the following sentence at the
beginning of the section: "The static pressure compensation
calculation has not been tested experimentally under controlled
conditions, and its estimates should be used with caution."
SUBSTANTIATION: These equations assume that the static pressure
can be added to the halon column pressure in order to compute the
halon leakage. However; the source of static pressure in most
enclosures is a leak in a duct that is at much higher pressures than
the expected halon column pressure. Therefore, the flow from this
leak in a duct that is at much high pressures than the expected halon
column pressure. Therefore, the flow from this leak will be constant
and it will not create a constant increase in pressure at all times. Our
initial calculations indicate a 30 percent decrease in hold time
(compared to the current calculation) when the static pressure is 10
percent of the column pressure. We are not aware of ;iny experiments that have been done to validate any of stadc pressure
calculations., Note that there are several reasons to stay away from
static pressure compensation even if the calculation is correct:
adjacent rooms may be at different pressures, and HVAC operation
or modification may change pressures.
COMMITTEE ACTION: Accept in Principle.
COMMITTEE STATEMENT: Refer to action in Proposal 12A-78
(Log #48).
"
(Log # 81)
12A- 114 - (B-2.7.1.7): Reject
SUBMITTER: David Saum and John Hupman, INHLTEC
RECOMMENDATION: Revise B-2.7.1.7 (no text available at this
time)
"Summary of changes: Add an alternative calculadon to c&npute
the hold time. correspondin,g to a 1 percent drop in the ha]on
concentrauon (typically from 6 percent to 5 percent) rather than the
current calculation which esdmates the hold time for the half
concentration (typically from 6 percent to 3 percent):"
SUBSTANTIATION: Ha]on discharge tests have conventionally been
performed by monitoring the halon concentration at the highest
protected level in the enclosure and defining failure when the
concentration drops from an initial 6 percen-t design concentration
to 5 percent which has been con.sidered to be the minimum
acceptable concentration. The proposed calculation would be more
in line with this previous discharge test experience. A limited amount
of test chamber ts available to provide a model for this calculation.
This data need to bereconfirmed in other test chambers and in field
tests.
C O M M ~ F I ~ E A C T I O N : Reject.
COMMrl-I~:E STATEMENT: No text provided by submitter.
(Log # 82)
12A. 115 - (B-2.7.1.7): Reject
SUBMYrTER: David Saum and John Hupman, INrFILTEC
RECOMMENDATION: Revise B-2.7.1.7 (exact text not available)
"Summary of changes: Revise equations 9, 10, 11 to assume a flow
exponent of 0.5 when the measured pressure is above half of the
column pressure and to assume a flow exponent of 0.65 when the
flow pressure is below half of the column pressure. This would allow
a conservative estimate of halon leakage no matter how far off the
measurement was from the column pressure. An alternative method
that should be included is a multipomt curve fit to determine the
actual flow exponent of the enclosure."
SUBSTANTIATION: The present method of selecting target
pressures is rather arbitrary. Ideally one would like to measure flow at
the worst case crack pressure which is haif the column pressure.
Equations 9-11 assume a flow exponent of 0.5 when they estimate the
crack pressure from the measurement that is close to column
pressure. This method is conservative as long as the measurement is
higher than the crack pressure. However, in bigger buildings it is ,
difficult toproduce a pressure as large as the crack pressure (about
0.4 in WC for a 130 ft building). By assuming a larger flow exponent
in this case, we can make conservative flow estimates with lower
pressure data. Of course, the most accurate method would be to
make an multipoint pressure/flow curve fir which could be used to
estimate any other values.
COMMITTEE ACTION: Reject.
COMMITTEE STATEMENT: No text provided by submitter.
581
NFPA 12A-
A92 TCR
(Log # 18)
12A. 116- (B-2.7.3): Reject
SUBMrrrER: WilliamEck_holm, FSSA
RECOMMENDATION: Revise to include calculation of it) at both
design concentration and at 80 percent of design concentration.
SUBSTANTIATION: Present method does not allow for degradation
to 80 percent of design concentration as is ailowed ifa discharge test
is conducted (paragraph A-1-7.4(E).
COMMF1WEE ACTION: Reject,
COMMITTEE STATEMENT: Refer to action in Proposal 12A-109
(Log #10). The calculation method calculates for time. The user can
increase the required holding time and therefore achieve the 80
percent interface criteria.
A=(1.271) {20.514)/( 12- 1)
(3)
= 0.0265 m
Pressurization
A = (1.271)~0868)/( 10+ I)
(3)
= 0.0265 m
Average
A ffi (0.0265 ~ 0.0265)/(2)
= 0.0265 m
BCLA = A - 0.0265 m 2
SUBSTANTIATION: The example must conform to proposed
changes in B-2.6.3.5 plus text per B-2.6.1.6.
COMMITTEE ACTION: Accept,
(Log # 88)
12A- 119- (13-2.9 (New)): Accept in Principle
SUBMJ:rI'~R: David Saum and J o h n Hupman, INFILTEC
RECOMMENDATION: Add new section on door fan calibration (132.9?)
"Door fans shall be recalibrated yearly and a certificate shall be
available for inspection at all integrity tests. The calibration shall be
performed according to techniques described in ASTM E???
~Callbration..." or equivalent. The certificate shall include the
following:
(Log # 64)
12A- 117- (15-2.7.3):Accept
SuBMrrrER: Colin C,enge, SheltairScientific,Ltd.
RECOMMENDATION:
Change the example to conform to
proposed changes in B-2.7.1.7.
"In B-2.7.3.4.2(d),change the exponent "1/0.5" to "2"
In B-2.7.3.4.2(e),change "I-.5"to "0.5"in 3 places.
In B-2.7.3.5.2(d), in (9)chan~e "1/0.5" to "2".
,
In B-2.7.3.5.2(e) change "1-.5 to "0.5 in 3 places.
' SUBSTANTIATION: The above changes are proposed to make the
example conform to proposed changes in 13-2.7.1.7.
COMM1TrFAE ACTION: Accept.
(a) Description of calibration facility and responsible technician.
(b) Date of calibration and serial n u m b e r of door fan.
(c) Roompressure gauge error estimates at 10, 15, 20 Pa (0.04,
0.06, and 0.08 in. we) measured by both ascending and descending
pressures (minimum).
(d) Fan calibration at a minimum of 3 leakage areas (approximate):
1.0, 0.25, and 0.05 sq m (8, 2, 0.5 sq ft) measured at a pressure of 10
Pa (0.04 in. we)."
SUBSTANTIATION: Without a specific requirement for re[[ular
recalibration, all door fan measurements of enclosure integrity are
estionable.
ACTION: Accept in Principle.
Add the following as 13-2.2.1.6:
"Door fan systems should be checked for calibration every 5 years
under controlled conditions and a certificate shall be available for
inspection at all integrity tests. The calibration shall be performed
according to manufacturers specifications."
"Calibration..." or equivalent. The certificate shall include the
following:
(a) Description ofcaiibration facility and responsible technician.
(b) Date of calibration and serial n u m b e r of door fan.
(c) Roompressure gauge error estimates at 8, 10, 12, 15, 20 and 40
Pa measuredby both ascending and descending pressures (mini-
(Log # 65)
12A- 118- (B-2.7.3): Accept
SUBMITrER: Colin Genge, Sheltair Scientific, Ltd.
RECOMMENDATION: Change the example to conform to
proposed changes in 13-2.6.3.5. In addition changes are shown to
demonstrate the target pressure range of the calculated required
pressure reduction per 13-2.6.1.3 a n d t h a t same reduction plus 30
percent.
Proposed changes are:
13-2.7.3.3.3 add -range" after "pressure", add "and B-2.6.1.6" after
"(per B-2.6.1.4)", add to -1-10 X 1.30 = -14 Pa" at end.
13-2.7.3.3.4 add "range" after,"pressure', add "to -1 + 10 X 1.3 = +12
Pa" at end.
• B-2.7.3.4.1 change Ca) to read: "Depressurize the enclosure into the 11 Pa to -14 Pa range with the door fan. Measure the airflow required
and pressure created (per B-2.6.1.4, .5 and .6)."
Q,, = 0.2046 m / s e e (depressurizlng to -12 Pa) in (b) change to
~Pre~urize the enclosure into the +9 Pa to +12 Pa range with the
door fan. Measure the airflow required and pressure created (per B2.6.1.7)"
3
"Q,, = 0.3480 m / s e c (pressurizing to +10 Pa)"
N O T E : The flows have been changed to those that would have to
be read by the door fan to get the results shown.
B-2.7.3.4.1 (c) change ".3069~to ".2046" and change ".3080" to
".2053"
B-2.7.3.4.1(d) change to:
EEDARTWORK "DepressurizationA= (1.271) (.2053)/( 12- 1)
mum).
(d) Fan calibration at a minimum of 3 leakage areas (approximate):
0.5, 0.25, and 0.05 sq m measured at a pressure of 10 Pa."
Change exisdngparagraph designation B-2.2.1.6 to 13-2.2.1.7.
COMMtt-I1~E STATEMENT: Clarification.
(Log # 84)
12A- 120 - (13-2.10 (New)): Accept
SUBMITrER: David Saum a n d J o h n Hupman, INFILTEC
RECOMMENDATION: Add new section on common causes of test
failures (13-2.10?)
"B-2.10 When discharge tests have been conducted after door fan
tests, failures have been observed for the following reasons:
(a) Incorrect data entry of parameters such as room volume and
d6or fan flow parameters.
(b) Lack of adequate flow return paths which caused the door fan
to estimate a tighter enclosure.
(c) Failure to inspect the seals (leaky) on the door in which the fan
was installed.
(d) Negative pressure leaks on floor of a room (caused by adJacent
elevator shaft).
(e) Psychological pressure on door fan technician to quickly
interpret complex test results to avoid cosdy delays in building
schedules.
(f) To much reliance on complex test results and not enough on
simple seaiing of lower enclosure leaks."
SUBSTANTIATION: These test failures provide valuable guidance
on test failure modes.
COMMITTEE ACTION: Accept.
(3)
= 0.1059 m 2
Pressurization A = (1,~71) (.3468)/( 10 + 1)
(3)
= 0.1059 m "
Average
A = (0.1059 + 0.1059)/(2)
= 0.1059 2
ELA = A = 0.1059 m
B-2.7.3.5.1 change (h) to read:
"Depressurize the enclosure below the ceiling with the door fan into
the -I1 Pa to -14 Pa range. Measure the airflow required and the
pressure creaw41 (per B-2.6.2.5,13-2.6.2.6 and 13-2.6.2.7):
Q,, = .0512 m " / s e c (depressurizing to-12 Pa)"
CRange (c) to read:
"Pressurize the enclosure below the ceiling with the door fan into
the +9 Pa to +12 Pa range. Measure the airflow required and the
pressure creategl (per B-2.6,2.8):
Q , = ,0871 m°/sec (pressurizing to +10 Pa)"
Change parts of (d) and (e) to read:
(d) Depressurization
n
Q,.= (.0512) ~(20+ 273)/(18 + 273)) v'o
(2)
~ = 0.0514 m " / s e c
Pressurization
O~ = (.0871))418 + 273)/(20.+ 273)) 0.5
(2)
.0.0868 m~/sec
(e) Depressurizadon
582
NFPA 12A ~ A92 TCR
(Log # 19)
I?.A- 121 - (C-1.9): Reject
SUBMITrEI~ William Eckholm, FSSA
R E C O M M E N D A T I O N : Add to publicadon list:
=Minimum Piping Requirements for Halon 1301 Systems" FSSA,
1989
SUBSTANTIATION: Paragraph A-1-10.1.1 and the piping tables are
taken from this document.
COMMrrFEE ACTION: Reject.
COMMITTEE STATEMENT: Document is not referenced in
Appendix.
Editorial Corrections
Ensure that all new terms are used throughout appendix.
Capitalize all defined terms throughout the document.
Add closing parenthesis after first C4 in equadon 11 of B-2.7.1.7.
Renumber equations as appropriate throughout.
583
NFPA 12A -- A92 TCR
Pre-engineered systems (packaged Systems) consist of system
components designed to be installed according to pretested
limitations as approved or listed by a testing laboratory. Preengineered systems may incorporate special nozzles, flow rates,
methods of application, nozzle placement, and pressurization levels,
that may differ from those detailed elsewhere in this standard. All
other requirements of the standard app1)'. Pre-engineered systems
shall be installed to protect hazards w~thm the limitations that have
been established by the testing laboratories where listed.
12A- 122 - (Entire Document): Accept
SUBM1TrER: Technical Committee on Halogenated Fire Extinshing Systems
COMMENDATION: Revise NFPA 1PA to more ciearly state the
requirements and to separate the mandatory from the nonmandatory
requirements to assist in making the document more usable,
enforceable and adoptable.
Revise the body of the standard and Appendix A as follows. "
SUBSTANTIATION: 1. Explanatory material, or wording which did
not state a requirement or was not essential to understanding a
requirement was deleted or relocated to the appendix, as appropriate.
2. Revised language to stipulate specific enforceable criteria.
a. Specific attention was given to revising existing mandatory text
that uses the word =may" and replacing it with phrases such as "shall,"
shall be permitted, to," or similar, wordmg.
.
.
.
b. Text that was mformanonal or explanatory tmplymg a reqmrement or permissive use was revised using "shall," "shall be permitted,"
or simile.- wording to properly stipulateintended requirements or
permmwe uses.
c. Terms such as adequate, suitable, were (whenever possible)
replaced with actual rec)uirements or the term should was deleted.
Advisory information with alternatives were placed in the Appendix.
3. Requirements that required a decision relative to a range of
choices of levels of safe.ty were revised to a specific minimum criteria.
4. The standard was divided into four separate chapters:
Chapter 1 General
Chapter 2 Components
Chapter 3 System Design
Chapter 4 Inspection, Maintenance Testing, and Training
5. Definitions essential to understanding the text were moved to
Section 1-4 on definitions
6. A thorough review of the document was conducted to ensure
conformity with the NFPA Manual of Style.
7. The TCR recommended changes were incorporated into the
applicable sections in the above.
8. To assist the reader, paragraph designations from the 1989
edition of NFPA 12A appear in parenthesis next to the proposed new
paragraph designations. (Body text only).
COMMITIXE ACTION: Accept.
~tl~
I-$ (1-4) Deiiuitions and Units.
I-3.I (I-4.1) Definitions. For purpose of clarification, the following
general terms used with special technical meanings in this standard
are defined:
Approved. Acceptable to the "authority having jurisdiction."
NOTE: The National Fire Protection Association does not
approve, inspect or certify any installations, procedures,
equipment, or materials nor does it approve or evaluate testing
laboratories. In determining the acceptability of installations
or procedures, equipment or materiah, the authority having
j'urisdiction may. base acceptance on compliance with NFPA or
other appropnate standards. In the absence of such standards,
said authority may require evidence of proper installation,
procedure or use. The authority having jurisdiction may also
refer to the listings or labeling practices of an organizauon
concerned with product evaluations which is in a position t o
determine compliance with appropriate standards for the
current production of listed items.
Authority HavlngJurlsdiction. The "authority having jurisdiction" is
the organization, office, or individual responsible for "approving"
equipment, an installation, or a procedure.
NOTE: The phrase "authority having jurisdiction" is used in
NFPA documents in a broad manner since jurisdictions and
"approval" agencies vary as do their responsibilities. Where
public safety is primary, the "authority having jurisdiction" may
be a federal, state, local, or other regional department or
individual such as a fire chief, fire marshal, chief of a fire
revention bureau, labor deparunent, health department,
ilding offidal,
electric/d inspector, or others having statutory authority. For
insurance purposes, an insurance inspection department,
rating bureau, or other insurance company representative may
be the =authority having jurisdiction." In many circumstances
the proper~ ownel or his delegated agent assumes the role of
the =authority having jurisdiction'; at government installations,
the commanding officer or deparunental official may be the
=authority having jurisdiction."
NFPA 12A
Standard on
Halon 1301 Fh-e Extinguishing Systems
1992 Edition
NOTICE: An asterisk (*) following the number or letter designating
a paragraph indicates explanatory material on that paragraph m
Appendix A.
Clearance. The air distance between Halon 1301 equipment,
including piping and nozzles, and unenclosed or unmsuiated live
electrical components at other than ground potential.
Information on referenced publications can be found in Chapter 5
and Appendix C.
Filling Density. The number of pounds of Halon 1301 per cuft of
container volume.
Chapter 1 General
Listed. Equipment or materials included in a list published by an
organization acceptable to the authority having jurisdiction and
concerned with product evaluation, that maintasns periodic
inspection of production of listed equipment or materials and whose
listing states either that the equipment or material meets appropriate
standards or has been tested andfound suitable for use in a specified
manner.
1-1 Scope. This standard contains minimum requirements for total
flooding Halon 1301 fire extinguishing systems. I t includes only the
essentials necessary to make the standard workable in the hands of
those skilled in this field. Portable Halon 1301 extinguishers are
covered in NFPA 10, Standardfor PortableFi~ Extinguishers.
Only those skilled in this work are competent to design and install
this equipment. It may be necessary for many of those charged with
purchasing, inspecting, testing, approving, operating, and maintaining this equipment to consult with an experienced and competent
fire protection engineer to effectively discharge their respective
duties.
NOTE: The means for identifying listed equipment mayvary
for each organization concerned with product evaluation, some
of which do not recognize equipment as listed unless it is also
labeled. The authority having jurisdiction should utilize the
system employed by the listing organization to identify a listed
product.
1-2 Purpose. This standard is prepared for the use and ~uidance of
those charged with purchasing, designing, installing, tesung,
inspecting, approving, listing, operating, and maintaining halogenated agent extinguishing systems (Halon 1301), so that such
equipment will function as intended throughout its life. Nothing in
this standard is intended to restrict new technologies or alternate
arrangements provided the level of safety prescribed by this standard
is notlowered.
Normally Occupied Area.* One that is intended for occupancy.
Shall. Indicates a mandatory requirement.
Should. Indicates a recommendation or that which is advised but
not required.
584
NFPA 12A -- A92 TCR
/
Other terms used with special technical meaning are defined or
explained where they occur in the standard.
1-4.2.5" (.2-1.1.1) Where halon systems are used, a fixed enclosure
shall beprovided about the hazard that is adequate to enable the
specifiedconcentration to be achieved and maintained for the
specified period of time.
,
1-3.2 (1-4.2) Units.
1-3.2.1 (1.4.2.1) Metric units of measurement in this sumdard are in
accordance with the modernized metric system known as the International System of Units (SI). Two units (liter and bar), outside of but
recognized by Sl, are commonly used in international fire protection.
These units are listed in Table I-3.2 with conversion factors.
1-4.2.6 (2-1.1.1) Halon 1301 shall only be used in enclosures where
ambient temperatures are between -70°F and 900°F (see A-I-5.1).
1-4.2.7 (1-5.4) Duration of Protection. An effective agent concentration shall be achieved, and be maintained for a suiti6ent period of
time to allow effective emergency action by trained personnel. This is
equally important in all clagses of fires since a persistent ignition
source (e.g., an arc, heat source, oxyacetylene torch, or "deep-seated" .
fire) can lead to a recurrence of the initial event once the agent has
dissipated. Halon 1301 extinguishing systems normally provide
protection for a period of minutes, but are exceptionally effective for
certain applications. "
1-3.2.2 (1-4.2.2) If avalue for measurement as given in this standard
is followed by an equivalent value in other units, the first stated is to
be regarded as the requirement. A given equivalent value may be
approximate.
"
Table I-$.2
Metric Conversion'Factors
Name of Unit
liter
cubic decimeter
pascal
bar
bar
Unit Symbol
L
dm s
Pa
bar
bar
I-/; (1-6) Safety.
1-5.1" (1-6.1) Hazards to PersonneL
Conversion Factor
1 gal = 3.785L
1 gal = 3.785 dm s
.1 psi = 6894.757 Pa
•1 psi = 0.0689 bar
1 bar = 105 Pa
I-/;.1.1 (1-6.1.1) Unnecessary exposure to Halon 1301 and its
decomposition products shall be avoided. Exposure to high
concentrations or for prolonged periods may produce dizziness,
impaired coordination, and disturbances in cardiac rhythm.
I-5.1.2" (I-6.1.2)Safety Requirements. Suitable safeguards shall be
provided to ensure prompt evacfiation and prevent entry into
hazardous atmospheres and also to provide means for prompt rescue
of any trapped personnel. ,Safety items such as personnel training,
warning slgns, discharge alarms, and self-contained breathing
equipmen~ shall be considered.
-
For. addttional conversions and m f o r m a t m n see A S T M E380, Standard for Metric
Praefect.
In Canada refer to Canadian Metric Practice Guzde, CSA Standard CAN3-Z234 1-79.
1-4 (1-/;) General Information.
I-/;.2" (1-6.2) Electrical Clearances. All system components shall he
located to maintain minimum clearances from live parts as shown in
Table 1-5.2.
1-4.1" (I-5.2.1) Halon I$01. Ha]on 1301 (bromotrifiuoromethane
CBrFa) is a colorless, odorless, electrically nonconductive gas that is
an e~ective medium for extinguishing fires.
The clearances given in Table 1-5.2 shall Be used for altitudes of
3,300 ft (1000 m) or less. At altitudes in excess of 3,300 ft (1000 m),
the clearance shall be increasedat the rate of 1 percent for each 330
ft (100 m) increase in altitude above 3,300 ft (1000 m).
1-4.2 (1-5.3) Use and Limitations.
• I-4.2.1 (1-5.3.1) Ha]on 1301 is included in theMonwea] Protocol on
Substances that Del~lete the Ozone Layer signed September 16, 1987.
The protocol pernuts continued availability of halogenated fire extinguishing agents at 1986 production levels. That Protocol, and subsequent
amendfnents, restrict the production of this agent. In addition, local
jurisdictions within some countries (e.g., the EPA in the U.S.A.) have
enacted further rules regulating theproduction, use, handling and
deposition of this agent. The user of this standard is advised to consult
local authorities for current regulations. Halon 1301 fire extinguishing
systems are useful within the limits of this standard in extinguishing fires
in specific hazards or equipment, and in occupancies where an electrically
nonconductive medium is essential or desirable, where cleanup of other
media presents a problem.
The selected clearance to ground shall sadsfy the greater of switching
surge or BIL duty, rather than being based on nominal voltage.
Table 1-5.2 Clearance from Halon I$01 Equipment
to Live Unlnaulated Electrical Components
1-4.2.2 (1-/;.3.2) Total flooding Halon 1301 fire extinguishing systems
are used primarily to protect hazards that are in enclosures or
equipment which, in resell, includes an enclosure to contain the
~_~alent. Some typical hazards that may be evaluated for the use of
on 1301 are as follows:
(a) Electrical and electronic hazards
(b) Telecommunications
(c) Flammable and combdstihle liquids and gases
(d) Other high valve assets.
1.4.2.3 (1-/;.$.$) Halon 1301 shall n o t b e used on the following:
(a) Certain chemicals or mixtures of chemicals such as celiulose
•nitrate and ~unpowder, which are capable of rapid oxidation in the
absence of mr.
Nominal
" System
Voltage (kv)
To 13.8
23
34.5
46
69
115
138
161
230
Maximum
System
Voltage (kv)
14.5
24.3
36.5
48.3
72.5
121
145
169
242
345
362
500
550
765
800
Design .
BIL
(kv) ,
110
150
200
250
350
550
650
750
900
1050
1050
1300
1500
1800
2050
Minilhum*
Clearance
(in.)
(mm)
7
178
10
254
13
330
17
432
25
635
42
1067
50
1270
58
1473
76
1930
84
2134
84
2134
104
2642
124
3150
144
3658
167
4242
*For voltages up to 161 kv, the clearances are taken from N F P A 70, National
Electrical Code® For voltageg of 230 kv and above, the.clearances are taken from
Table 124 of A N S I C-2, Nattonal Elecmcal Safety Code
(b) Reactive metals such as sodium, potassium, magnesium,
titanium, zirconium, uranium, and plutonium.
In C a n a d a , refer to Canadzan Electrzcal Code, Part I, C S A Standard C22 1-1986
(c) Metal hydrides.
NOTE: BIL values are expressed as kilovolts (kv), the number
being the crest value of the full wave lmpuls'e test that the electrical equipment is designed to withstand. For BIL values not listed in the table, clearances may be found by interpolation.
(d) Chemicals capable ofundergoingautothermal decomposition,
such as certain organic peroxides and hydrazine.
1.4.2.4 (1-/;.3./;) Electrostatic charging'of nongrounded conductors
may occur during the discharge of liquefied gases. These conductors
may discharge to other objects, causing an electric arc of sufficient
energy to imtiate an explosion. (SeeNFPA 77, Recommended Practice on
Static Electricity.)
The clearance between uninsuiated energized parts of the electrical
system equipment and any portion of the Halon 1301 system shall not
he less than the minimum clearance provided elsewhere for electrical
system insulations on any individual component.
585
~'
NFPA 12A -- A92 TCR
superpressurizadon level. A label that will require the proper return
o f the agent shall be atFtxed to all new and cresting containers. Filled
containers must be returned for recycling or recovery of the agent
when no longer needed.
1-5.2.1 (1-6.2.1) When the design BIL is not available, and when
nominal voltage is used for the design criteria, the highest minimum
clearance listed for this group shall be used.
Chapter 2 Components
2-1 Halon 1301 Supply.
2-1.1 (1-9.1) Quantifies.
2-1.1.1 (1-9.1.1) The amount of Halon 1301 in the system shall be at
least suflldent for the largest single haza/d protected or group of
hazards that are to be protected simultaneously.
2-1.1.2 (1-9.1..2) Where required, the reserve quantity shall be as
many multiples of these minimum amounts as the authority having
jurisdiction considers necessary. The time needed to obtain Halon
1301 for replenishment to restore systems to operating conditions
shall be considered a major factor in determining the reserve supply
needed.
2-1.4.3 (1-9.4.3) The Halon 1301 containers used in these systems
shall be designed to meet the requirements of the U.S. De . p ~ m e n t
of Transportation or the Canadian Transport Commission, if used as
shipping containers. If not a shipping container, it shall be designed,
fabncated, inspected, certified, and stamped in accordance with
•Section VIII of the ASME Unfired Pressure Vessel Code; independent
inspection and certification is recommended. The designpressure
shall be suitable for the maximum pressure developed at I30°F
(55°C) or at the maximum controlled temperature limit.
2-1.4.4 (1-9.4.4) A reliable means of indication, other than weighing,
shall be provided to determine the pressure in refillable containers.
The means of indication shall account for variation of container
pressure with temperature.
2-1.4.5 (1.9.4.5) When manifolded, containers shall be adequately
mounted and suitably supported in a rack that provides for convenient individual servicing or content weighings. Automatic means
shall be provided to prevent agent loss from the manifold if the
system is operated when any containers are removed for maintenance.
2-1.1.3 (1-9.1.3) Where uninterrupted protection is required, both
primary and reserve supply shall be permanently connected to the
distribution piping and arranged for easy changeover.
2-1.2 (1-9.2) Quality. The Halon 1301 shall complywith the
requirements of Table 2-1.2.
2-1.4.6 (1-9.4.6) In a multiple cylinder system, all cylinders supplying
the same manifold outlet for distribution of agent shall be interchangeable and of one select size and charge.
Tabl~ 2-1.2
Requirements for Halon 1301 (Bromotrlflu?romethane)
Property
Bromotrifluoromethane, mole percent, minimum
Other Halocarbons, mole percent, maximum
Acidity ppm (by weight), maximum
Water Content, percent by weight, maximum
Boiling Point °C at 760 mmHg
Boiling Range, °C, 5 to 85 percent distilled
High Boiling,lmpurities, grams/100 ml maximum
Suspended Matter or Sediment
2-1.4.7 (1-9.4.7) Storage temperatures shall not exceed 130=F (55°C)
nor be less than -20°F (-29°C)for total flooding systems unless the
system is designed for proper operation with storage temperatures
outside this range. External heating or cooling shall be used to keep
the temperature of the storage container within desired ranges.
Requirement
, 99 6
0.4
3.0
0 001
-57 75
0.3
0.05
None visible
2-2 (1-10) Distribution.
2-2.1" (1-10.1) Piping.
2-2.1.1" (1-10.I.1) Piping shall be of noncombustlble material having
physical and chemicalcharacteristics such that its integrity under "
stress can be predicted with reliabiUty. Special corrosion-resistant
materials or coatings shall be required in severely corrosive atmospheres. The thickness of t h e p i p e wall shall be calculated in
accordance with ANSI B31.1, Power Piping Code. The internal
pressure for this calculation shall be the maximum storage pressure 3
at the maximum storage temperature [a 70 lb per c u f t (1121 k g / m )
density shall be asstimed], but in no case shall be less than the
following:
For 360 psig charging pressure, an internal pressure of 620 psi
(130°F);
For 600 psig charging pressure, an internal pressure of 1,000 psi
(130°F).
NOTE: For test procedures refer to MIL-M-12218C available
from Naval Publications and Forms Center, 5801 Tabor Avenue,
Philadelphia, PA 19120.
2-1.3 (1-9.3) Storage Container Arrangement.
2-1.3.1 (1-9.3.1) Storage containers and accessories shall be so
located and arranged that inspection, testing, recharging, and other
maintenance is facilitated and interruption of protection is held to a
minimum.
2-1.3.2 (1-9.3.2) Storage containers shallbe located as close as
possible to the hazard or hazards they protect,but shallnot bc
exposed to a firein a manner likelyto imp~r system performance.
If higher storage temperatures are approved for a given system, the
internal pressure shallbe adjusted to the maximum internal pressure
at maximum temperature. In performing this calculation, aUjoint
.factors and threading, grooving, or welding allowances shall be taken
into account.
2-1.3.3 (I-9.3.3) Storage containers shall not be located where they
are likelyto be subject to severe weather conditions or mechanical,
chemical, or other damage. Where excessiveclimaticor mechanical
exposures are expected, suitablesafeguards or enclosures shallbe'
provided.
2-2.1.2 (1-10.1.2) Cast-iron pipe, steel pipe conforming to ASTM
A120, or nonmetallic pipe shall not be used.
2-2.1.3 (1-10.1.3) Flexible piping, tubing, or hoses (including
connections) where used shall be of approved materials and pressure
ratings.
2-1.3.4 (I-9.3.4) Storage containers shallbe securely mounted per
the manufacturer's listedor approved installationmanual. Thxs shall
include mounting the contairfdrto the appropriate mounting
surface.
2-2.1.4 Each pipe section shall be cleaned internally after preparation and before assembly by means of swabbing, utilizing a suitable
nonflammable cleaner. The piping network shall be free of
particulate matter and oil residue before installation of nozzles or
discharge devices.
2-1.4 (I-9.4) Storage Containers.
2-1.4.1" (1-9.4.1) The Halon 1301 supply shall be stored in containers designed to hold Halon 1301 in liquefied form at ambient
temperatures. Containers shall not be charged to a filling density
greater than 70 lb per c u f t (1121 kg/mS). They shall be
superpressurized with dry nitrogen to 360 psig =5 percent or 600psig
:e.5 percent total pressure at 70°F (25.84 bars :~, percent or 42.38 bars
:~, percent total pressure at 21°C).
2-2.1.5" (1-10.3.4) In systems where valve arrangement introduces
sections of closed piping, such sections shall be equipped with
pressure relief devices or the valves shall be designedto prevent
entrapment of liquid. In systems using pressure operate-d cylinder.
valves, means shall be provided to vent any container leakage that
could build up pressure in the pilot system and cause unwanted
opening of the cylinder valve. The means of pressure venting shall be
arranged so as not to prevent reliable operation of the cylinder valve.
Exception: Listed pre-engineeredsystems may have different pressurization
levelsper &aion 1-2.
2-1.4.2 (1-9.4.2) Each container shall have a permanent nameplate
specifying the agent, tare, and gross weight in addition to the
586
NFPA 12A -- A92 TCR
2-2.1.6 All pressure relief devices shall be of such design and solocated that the discharge therefrom will not injure personnel or be
otherwise objectionable.
2-5.2.2 (1-8.2.2) Adequate and reliable primary and 24-hour
minimum standby sources of energy shall be used to provide for
operation of the detection, signaling, control, and actuation
requirements of the system.
2-2.2 (1-10.2.1) Piping Joints. Piping joints of other than the screwed
or flanged type shall be listed or approved for this application.
2-S.$ (1-8.3) Operating Devices.
2-2.$* (1-10.2.2) Fittings. Fittings for 600 psig charging pressure
systems shall have a minimum working pressure of 1,000 psi. Systems
utilizing 360 psig charging pressure shall use fittings having a
• minimum working pressure of 620 psi.
2-2.3.1 (1-10.2.2) Class 150Ib and cast-iron fittings shall not be used.
2-2.$.2 (1-10.2.4) All.threads used in joints and fittings shall conform
to ANSI B1.20.1. Joint compound, tape, or thread lubricant shall be
,applied only to the male threads of the joint.
2-2.3.$ (1-10.2.5) Welding alloys shall have a melting point above
1000°F (538°C).
2-2.$.4 (1-10.2.5.1) Welding shall be performed in accordance with
Section IX, "Qualification Standard for Welding and Brazing
Procedures, Welders, Brazers and Welding 'and Brazing Operators" of
the ASME Boiler and Pressure Vessel Code.
2-2.$.5 (1-10.2.6) Where copper, stainless steel, or other suitable
tubing is joined with compression-type fittings, the manufacturer's
pressure-temperature ratings for the fitting shall not be exceeded.
2-2.4 (1-10.4) Valves.
2-2.4.1 (1-10.4.1) All valves shall be listed or approved for .the
intended use.
2-2.4.2 (1-10.4.2) Valves shall be protected against mechanical,
chemical, or other damage.
2-2.4.$ Special corrosion resistant materials or coatingsshall be used
in severely corrosive atmospheres.
2-2.5 (I-10.5) Discharge Nozzles.
2-2.5.1 (1-10.5.1) Discharge nozzles shall be listed for Use including
the flow characteristics and area of coverage. Discharge orifices shall
be of corrosion-resistant metal.
2-3.3.1 (1-8.3.1) Operating devices shall include Halon 1301
releasing devices or valves, discharge controls, and shutdown
equipment necessary for successful peformance of the system..
2-3.3.2 (1-8.3.2) Operation shall be by listed or approved mechanical,
electrical, or pneumatic means. An adequate and reliable source of
energy shall be used.
2-3.3.3 (1-8.3.3) All devices shall be designed for the service they will
encounter and shall not be readily rendered inoperative or susceptible to accidental operation. De,aces shall be normally designed to
function properly from -20°F to 150°F (-29°C to 65°C) or marked to
indicate temperature limitations.
2-$;$.4 (I-8.$.4) All devices shall be located, installed, or suitably
protected so that they are not subject to mechanical, chemical, or
other damage that would render them inoperative.
2-$.$.5 (1-8.$.5) The normal manual control(s) for actuation shall be
located for easy accessibility at all times, includingtime of fire within
the protected area. ,The manual control(s) shallbe of distinct
appearance and clearly recognizable for the purpose intended.
Operation of this control shall cause the complete system to operate
in its normal fashion.
2-3.3.0 (I-8.$.6) An emergency release of the system resulting from a
single manual operation shall be provided. This shall be accomplished by a mechanical manual release or by an electrical manual
release when the control equipment monitors the battery voltage
level of the standby battery supply and will provide a low battery
signal. The emergency release shall cause simultaneous operation of
automatically operated valves controlling agent release and distribution.
2-3.3.7* (I-8.3.7) Manual controls shall not require a pull of more
than 40 Ib (178 newtons) nor a movement of more than 14 in. (356
mm) to secure operation. At least one manual control for activation
shall be located not more than 5 ft (1.5 m) above the floor.
2-$.3.8 (1-8.$.8) Where gas pressure from the system or pilot
containers is used as a means for releasing the remaining containers
the supply and discharge rate shall be deslgned for releasing all of the
remammg containers.
2-2.5.2 (1-10.5.2) Special corrosion-resistant materials or coatings
shall be required in severely corrosive atmospheres.
2-2.5.$* (1-I0.5.4) Discharge nozzles shall be permanendy marked to
identify the manufacturer as well as the type and size of the orifice.
2-3.3.9 (1-8.3.9) All devices for shutting do~/n supplementary
equipment shall be considered integral parts of the system and shall
function with the system operation.
,
2-2.5.4 (I-10.5.5) Where clogging by external foreign' materials is
likely, discharge nozzles shaIlbe provided with frangible discs, blow
off"caps, or other suitable devices. These devices shall provide an
unobstructed opening upon system operation and shall be located so
they will not injure personnel.
.
2-3.3.10 (I-8.3.10) All manual operating devices shall be identified as
to the hazard they protect.
2-3.4 (1-8.4) Control Equipment.
2-3 (1-8) Detection, Actuation, and Control Systems.
2-3.4.1 (1-8.4.1) Electric Control Equipment. The control equipment
shall supervise the actuadng devices and associated wiring and, as
required, cause actuation. The control equipment shall be specificall}~listed or approved for the number and type of actuating devices
utihzed and their compatibility shall have been listed or approved.
2-$.1 (1,8.1) Detection, actuation, alarm, and control systems shall be
installed, tested, and maintained in accordance with appropriate
NFPA protective signaling systems standards (see?WPA 70, National
Elect~cal Code";NFPA 72, Standard for the Installation, Maintenance, and
Use of Proteaive Signaling Systems; and NFPA 72E, Standard on Automatic
FireDetectors. In Canada referto CAN/ULC S524-M86, Standard for the
Installation ofFireAlarm Systems, and CAN/ULC $529-M87, Smoke
Detectorsfor FireAlarm Systems).
2-3.4.2 (1-8.4.2) Pneumatic Control Equipment. Where pneumatic
control equipment is used, the lines shall be protected against "
crimping and mechanical damage. Where installations could be
exposed to conditions that could lead to loss of integrity of the
pneumatic lines, special iprecautions shall be taken. T h e control
equipment shall be specifically listed or a~pproved for the number and
type of actuating devaces t~tilized and their compatibility shall have
been listed or approved.
.
2-$.1.1 (1-8.1.1) Automatic detection and automatic actuation shall
be used.
Exception: Manual-only actuation may be used if acceptableto the authority
having jurisdiction.
2-$.5 (1-8.5) OperatingAlarms and Indicators.
2-$.2 (I-8.2) Automatic Detection.
2-3.5.1 (1-8.5.1) Alarms or indicators or both shall be used to indicate
the operation of the system, hazards to personnel, or failure of any
supervised device. The type (audible, wsual, or olfactory), number,
and location of the devices shall be such that their purpose is
satisfactorily accomplished. The extent and type of alarms or
indicator equipment or both shall be approved.
2-3.2.1" (1-8.2.1) Automatic detection shall be by any listed or
approved method,or device capable of detecting and indicating heat,
flame, smoke, combustible vapors, or an abnormal condition in the
hazard, such as process trouble, that is likely to produce fire.
587
NFPA 12A m A92 TCR
2-3.5.2 (1-8.5.2) Audible and highly visible alarms shall be provided
to give positive warning of discharge. The operation of the warning
. devices shall be continued after Halon discharge, until positive action
has been taken to acknowledge the alarm and proceed with
appropriate action.
3.1.2.5 (1-7.2.5) An as-built instruction and maintenance manual that
includes a full sequence of operation and a full set of drawings and
calculations shall be maintained in a dearly identified protective
enclosure at or near the system control panel.
3.1.3 (1-7.3) Approval of Plans.
2-8.5.8* (1-8.5.3") Abort switches are generally not recommended.
However, where provided they shall be locatedonly within the
protected area and shall be of a type that requires constant manual
pressure to cause abort. The abort switch shall not be of a type that
would allow the system to be left in an aborted mode without
someone present. In all cases, the normal manual and emergency
manual control shall override the abort function. Operation of the
abort function shall result in both audible and distinct visuai
indication of system impairment. The abort switch shall be dearly
recognizable for the pui-pose intended.
3.1.$.1 (1-10.6.4) Nozzle orifice sizes shall be selected to achieve the
designed flow rate. The nozzle must be selected by consulting the
discharge characterhdc information in the manufacturer's listed
design manual. Flow should be calculated on the basis of an average
container pressure during discharge, taking into account the original
pressurization level, storage f-filing density, and percent in piping for
70°F (21°C) storage temperature as shown in Figure A-3-2.S(e).
3-1.$.2 (1-7.3.2) When field condidous necessitate any material
change from approved plans, the change shall be submitted for
approval.
2-3.5.4 (1-8.5.4) Alarms indicating failure of supervised devices or
equipment shall give prompt and positive indication of any failure
and shall be distinctive from alarms indicating operation or hazardous conditions.
3.1.3.3 (1-7.3.3.) When such material changes from approved plans
are made, corrected "as built" plans shall be provided.
3-2* (1-10.6) System Flow Calculation&
2-3.5.5 (1-8.5.5) Warning and instruction signs at entrances to and
inside, protected are:is shall be provided.
3-2.1 (I-I0.6.1) As part of the design procedure, system flow
calculations shall be performed using a listed calculation method.
The system design shall be within the manufacturer's listed limitadons.
2-3.5.6 (1-8.5.6) Time delays shall be used onlywhere discharge delay
is required for personnel evacuation or to prepare the hazard area
for discharge. Time delays shall not be used as a means of confirming operation of a detection device before automatic actuation
3-2.2 (1-10.4.3) Valves shall be rated for equivalent length in terms of
the pipe or tubing sizes with which they will be used. The equivalent
length of container valves shall be listed and shall include siphon
tube, valve, discharge head, and flexible connector.
OCCUrs.
2-3.6* (1-8.6) Unwanted System Operation. Care shall be taken to
thoroughly evaluate and correct any factors that may result in
unwanted discharges.
3.2.3* The nozzle and fitting orientation shall be in accordance with
the manufacturer's listed limitations to ensure proper system
performance.
Chapter 3 System Design
3-1 (1-7) Specifications, Plans, and Approvals.
3.2.3.I (I-7.3.1) Plans and calculations shall be submitted for
approval before work starts,
3-1.1 (1-7.1) Specifications. Specifications for Halon 1301 fire
extinguishing systems shall be prepared under the supervision of a
person fully experienced and qualified in the design of Halon 1301
extingnishingsystems and with the advice of the authority having
jurisdiction. The specifications shall include all pertinent items
necessary for the proper design of the system such as the designation
of the authority having jurisdiction, variances from the standard to be
permitted by the authority having jurisdiction, and the type and
extent of the approval testing to be performed after installation of the
system.
3-2.4 (1-10.6.3) If the final installation varies from the prepared
calculations, new calculations representing the "As-Built" installation
shall be prepared.
3-2.5 (2-1.1.3) Halon 1301 total floodin~ systems shall not be used in
concentrations greater than 10 percent m normally occupied areas.
Areas that may contain I0 percent Ha]on 1301 shall be evacuated
immediately upon discharge of the agent. Where egress cannot be
accomplished within 1 minute, Ha]on 1801 total flooding systems
shall not be used in normally occupied areas in concentrauons
greater than 7 percent. (SeeA-l-5,1.)
3-1.2 (1-7.2) Plans.
3-1.2.1 (1-7.2.1) Plans and calculations shall be submitted for
approval to the authority having jurisdiction before installation
begins. Their preparation shallbe entrusted to none butpersons
full), experienced and qualified in the design of Halon 1301
exungmshing systems.
3.2.6 (2-1.1.4) Halon 130] total flooding systems utilizing concentrations greater than I0 percent but not exceeding 15 percent may be
used in areas not normally occupied, provided egreks can be
accomplished within 30 seconds. Where egress cannot be accomplishedwithin 30 seconds or concentrations greater than 15 percent
must be used, provisions shall be made to prevent inhalation by
• personnel. (SeeA-1-5.1.)
3-1.2.2 (1-7.2.2) Theseplans shall be drawn to an indicated scgle or
be suitably dimensionedand shall be made so they can be easily
reproduced.
3.8* (2-2.2) Enclosure.
3-1.2.3 (1-7.2.3) These plans shall contain sufficient detail to enable
an evaluation of the hazard(s) and the effectiveness of the system.
The detail of the hazards shall include the materials involved in the
hazards, the location of the hazards, the enclosure or limits and
isolation of the hazards, and the exposures to the hazards.
3.3.1 (2-2.2.1) In the design of totai flooding systems, the characteristics of the enclosure shall be considei'ed as follows:
3.3.2 (2-2.2.2) For all types of fires, the area of unclosable openings
shall be kept to a minimum. The authority having jurisdiction may
require tests to assure proper performance as defined by this
standard.
3-1.2.4 (1-7.2.4) The detail on the system shall include information
and calculations on the amount of Haion 1301; container storage
pressure; internal volume of the container; the location, type, and
flow rate of each nozzle including equivalent orifice area;the
location, size, and equivalent lengths of pipe, fittings, and hose; and
the location and size of the storage facility. Details of pipe size
reduction method and orientation of tees shall be clearly indicated.
Information shall be submitted pertaining to the locatlon and
funcdon of the detection devices, operating devices, auxiliary
equipment, and electrical circuitry, if used. Apparatus and devices
used shall be identified. Any special features shall be adequately
explained. The manufacturer's version of the flow calculation
rogram shall be identified on the computer calculationprilat out.
nly the currently listed calculation method shall be used.
3.3.3* (2.2.2.3) To prevent loss of agent through openings to
adjacent hazards or work areas, openings shallbe permanently sealed
or equipped with automatic closures. Where reasonable confinement
of agent is not practicable, protection shall be extended to include
the adjacent connected hazards or work areas.
3-8.4 (2-2.2.4) Forced-air ventilating systems including in-room air
conditioning units shall be shut down or closed automatically where
their continued operation would adversely affect the performance of
the Halon 1301 system or restflt in propagation of the fire.
3-4 (2-3) Design Concentration Requirements.
588
NFPA
12A m A92 TCR
3-4.1" (2-3.2) For a particular fuel, either flame extinguishment or
incrting concentrations shallbe used.
3-4.2.1" (2-4.2) Solid Surface F'n'es. To protect materials that do not
develop deep-seated fires, a minimum concentration of 5 percent
shallbe used.
3-4.1.1 (2-3.2)Inertlng. The inerting concentrations shallbe used
where conditions for subsequent rcflash or explosion could exist.
These conditions are when both:
3-4.2.2 (2-4.3.2) Deep-Seated Fn'es. Where the solid material is in
such a form that a deep-seated fire can be established before a flame
extinguishing concentration has been achieved, provision shall be
made to the satisfaction of the authority having jurisdiction for means
to effect complete extinguishment of the fire.
(a) The quantity of fuel permitted in the enclosure is sufficientto
develop a concentration equal to or greater than one-half of,the
lower flammable limitthroughout the enclosure, and
3-5 (2-5) Determination of Halon 1301 Quantity for Total H o o d l n g
Systems.
(b) The volatilityof the fuel before the fireis sufficientto reach ~ e
lower flammable limitin air (maximum ambient temperature or fuel
temperature exceeds the close cup flash point temperature) or the
system response is not rapid enough to detect and extinguish the fire
before the volatility of the fuel is increased to a dangerofls level as a
result of the fire.
S-5.1" (2-5.2) Total Flooding Quantity. The amount of Halon 1301
required to achieve the design concentration shall be calculated from
the following formula:
V
CAUTION: Under certain conditions, it may be dangerous to
extinguish a burning gas jet. As a first measure, the gas supply
should be shut off.
"
W
(2-3.2.1) The minimum design concentrations specified in Table 34.1.1 shall be used to inert atmospheres involving severa~flammable
liquids and gases. Design inerting concentrations not given in Table
3-4.1.1 shallbe determined by test plus a 10 percent safety factor.
The minimum design concentration shall be 5 percent.
--
-
- -
s
(
C
100 -
C
/
s = 2.2062 + . 0 0 5 0 4 6 t
where t = minimum anticipated temperature of the protected
volume, °F
(s = 0.147 81 + .000 567 t
Table 3-4.1.1
H a l o n 1301 Design Concentrations for Inerfing
where t = minimum anticipated temperature of the protected
volume, °C)
C = Halon 1301 concentration, percent by volume.
'
Fuel
M i n i m u m Conc. % by Volume*
Acetone
Benzene
Ethanol
Ethylene
Hydrogen
Methane
n-Heptane
Propane
7.6
5.0
11.1
13.2
31.4
V = Net volume of hazard, cuft (mS). (Enclosed volume minus fixed
structures impervious to halon)
J
This calculation includes an allowance for normal leakage from a
"tight"enclosure due to agent expansion.
7.7
6:9
3-5.2 (2-5.1) In addition to the concentration requirements,
additional quantitiesof agent are required to compensate for any
special conditions that would affectthe extinguisfu'ngefficiency.
6.7
3-6* (2-5.3) Altitude Adjustments. The desil~'n quantity of Halon
1301 shah be adjusted to compensate for alutudes of more than 3000
ft (1000 m) above or below sea level, and pressures other than
atmospheric. It shall be the responsibility-of the system designer to
show that this has been taken into account in the design of a system.
"For references, see Reference (4) Appendix C-1.7.
NOTE: Includes a safety factor of 10 percent added to experimental values.
3-4.1.2" (2-3.2.2(d)) Flame Extinguishment. The minimum design
concentrations specified in Table 3-4.1.2 shall be used to extingmsh
normal fires involving several flammable liquids and gases. Design
flame extinguishment concentrations not g~ven in Table 3-4.1.2 shall
be obtained by test plus a 20 percent safety factor. Minimum design
concentrations shallbe 5 percent.
/
3-7 (2-6) Distribution System.
3-7.1" (2-6.2) Rate of Application.
3-7.1.1 (2.6.2.1) The minimum design ~ t e of application shall be
based on the quantity of agent required for the desired concentration
and the time allottedto achieve the desired concentration.
Table 3-4.1.2
Halon 1301 Design Concentration for Flame
Extinguhhment (In 25°C at I atm)
Fuel
Acetone
Benzene
Ethanol
Ethylene
Methane
n-Heptane
Propane
NOTE.
,
3-7.1.2 (2-6.2.2) Discharge Time. The agent discharge shall be
substantially completed in a nominal 10 seconds or as otherwise
required by the authority having jurisdiction.
Minimum Design
Concentration,
% by Volume
5.0
5.0
5.0
8.2
5.0
5.0
5.2
This period shall be measured as the interval between the first
appearance of liquid at the nozzle and the time when the discharge
becomes predominandy gaseous. This point is distinguished by a
marked change in both the sound and the appearance of the
discharge.
3-7.2* (2-6.3.4) When an extended discharge is necessary the rate
shall be sufficient to maintain the desired concentration for the
' duration of application.
3-8 (2-6.5) N o z z l e Choice and Location.
See A-2-3 for basis of this table
3-8.1 (2.6.5.1) Nozzles shall be of the type listed for the intended
purpose shall be placed within the protected enclosure in compliance
with listed limitations with regard to spacing, floor coverage, and
alignment.
i
NOTE: See A-3-4.2.1 for basis of this table.
$-4.1.3 (2-3.2.3) For combinations of fuels, the flame extinguishment
or inerting value for the fuel requiring the greatest concentration
shall be used unless tests are made on the actual mixture.
3-8.2 (2-6.5.2) The type of nozzles selected, their number, and their
placement shall be such that the design concentration will be
established in all parts of the hazard enclosure and such that the
discharge will not unduly splash flammable liquids or create dust
clouds that might extend the fire, create an explosion, or otherwise
adversely affect the contents or integrity of the enclosure.
$-4.2 (2-4.1) F"n'es in Solid Materials. Flammable solids maybe
classed as those that do not develop deep-seated fires and those that
do.
,
589
NFPA 12A - - A 9 2 TCR
Chapter 4 (I-11) Inspection, Maintenance, Testing and Training.
4-1" (1-11.1) Inspection and Tests.
(0 Hose assembly passing the test must be completely dried
internally. If heat Is used f-or drying, the temperature must not
exceed 150°F (66°C).
4-1.1 (1-11.1.1) At least annually, all systems shall be thoroughly
inspected and tested for proper operation by competent personnel.
(g) Hose assemblies falling a hydrostatic test must be marked and
destroyed. They shall be replaced with new assemblies.
4-1.2 (1-11.1.4) The inspection report with recommendations shall
be filed with the owner.
(h) Each hose assembly passing the hydrostatic test shall be marked
to show the date of test.
4-1.8 (1-11.1.6) At least semiannually, the agent quantity and
pressure ofref'fllable containers shallbe checked, ifa container
shows a loss in net weight of more than 5 percent or a loss in pressure
(adjusted for temperature) of more than 10 percent, it shall be
refilled or replaced. When the amount of agent in the container is
determined by special measuring devices in lieu of weighing, these
devices shall be listed.
4-$.2 (1-11.1.9.2) Testing. All hoses shall be tested every five years in
accordance with 4-3.1.
)
4-4 Enclosure Inspection. At least every six months the halon
protected enclosure shall be thoroughly inspected to determine if
penetrations or other changes have occurred that could adversely
affect halon leakage.
Where the inspection indicates that conditions that could result in
inability to maifitain the halon concentration, they shall be corrected.
If uncertainty still exists, the enclosures shall be re-tested for integrity.
4-1.4" (1-11.1.6) All halon removed from refillable containers during
service or maintenance procedures shall be collected and recycled.
4-1.5 (1-11.1.7) Factory-charged nonrefiUable containers that do not
have a means of pressure indication shall be weighed at least
semiannually. Ifa container shows a loss in net weight of more than 5
percent, it shall be replaced. All factory-charged nonrefillable
containers removed from useful service shall be returned for
recycling of the agent.
4-5 (1-11.2) Maintenance.
,t-5. I ( I-I 1.2. I ) These systems shall be maintained in full operating
condition at all times. Use, impairment, and restoration of this protection
shall be reported promptly to the authority havingjurlsdiction.
4-5.2 (I-11.2.2) Any troubles or impairments shall be corrected at
once by competent personnel.
4-1.6 (1-11.1.8) The weight and pressure of the container shall be
recorded on a tag attached to the container.
4-5.$ Any penetrations made through the halon ~rotected enclosure
shall be sealed immediately. The method of sealing shall restore the
original fire resistance rating of the enclosure.
4-2 (1-9.4.5) Container Test.
4-2.1 (1-9.4.5.1) D.O.T., C.T.C, or similar design Halon 1301
cylinders shall not be recharged without a retest if more than five
years have elapsed since the date of the last test and inspection. The
retest may consist of a complete visual inspection as described in the
Code of Federal Regulations, Tide 49, Section 173.34(e) (10).
4.45 (I-I I.$) Tra!n;ng. Allpersons who may be expected to inspect,
test, maintain, or operate fire extinguishing systems shall be
thoroughly trained and kept thoroughly trained in the functions they
are expected to perform.
4-2.2 (1-9.4.5.2) Cylinders continuously in service without discharging shall be given a complete external visual inspection every five
yefirs, in accordance witfi Compressed Gas Association pamphlet CA5,
Section 3; except thatlthe cylinders need not be emptied or stamped
while under pressure.
4-6.1 Personnel working in a halon protected enclosure shall receive
training regarding halon safety issues.
1Subpart C, Section 178.36 to and including 178.68 of Tide 49,
Transportation, Code of Federal Regu_lations, Parts 170-190.
Available from the Superintendent of Documents, U.S. Government
Printing Office, Washington, DC 20401. In Canada, the corresponding information is set forth in the "Canadian Transport Commission's
Re~. lations for Transportation of Dangerous Commodities by Rail, ~
av',ulable from the Queen's Printer, Ottawa, Ontario.
4-7.1 (1-7.4.1) The completed system shall be tested by qualified
personnel to meet the approval of the authority having jurisdiction.
Only listed or approved equipment and devices shall be used in the
systems. To determine that the system has been properly installed
and will function as specified, the following tests shall be performed.
4-7* (1-7.4) Approval of Insta~dons.
4-7.1.1 Verify that the protected enclosure conforms to the construction specifications.
/
4-2.3 (1-9.4.5.3) Where external visual inspection indicates that the
container has been damaged, additional strength tests shall be
required. Caution: If additional tests used include hydrostatic
testing, containers should be thoroughly 'dried before refilling.
4-7.2 lustallation Acceptance.
4-7.2.1 (I-7.4.1.3(A)) Mechanical acceptance:
(a) The piping distribution system shall be inspected to determine
that it is in compliance with the system drawings and the hydraulic
calculations indicated on the computer printout associatedwith each
agent storage container piping and nozzle configuration.
4-2.4 (1-9.4.5.4) Before recharging a container, a visual inspection of
its interior shall be performed.
4-3 (1-11.1.9) Hose Test. All system hoses shali be examined '
annually for damage. If visual examination shows any deficiency, the
hose shall be,immediately replaced or tested as specified in 4-3.1:
(b) Nozzles and pipe size shall be in accordance with system
drawings. Means of pipe size reduction and attitudes of tees shall be
checked for conformance to the design.
4-$.1 (1-11.1.9.1) All hoses shall be tested at 1500 psi for 600 psi
charging pressure systems, and at 900 psi for 360 psi charging
pressure systems.
(c) Piping joints, discharge nozzles, and piping supports shall be
securely fastened to prevent unacceptable vertical or lateral movement during discharge.
(a) Remove the hose from any attachment.
(d) During assembly, the piping distribution system shall be
inspected internally to detect the possibility of any oil or particulate
matter soiling the hazard area or affecting the agent distribution due
to a reduction in the effective nozzle orifice area.
(b) The hose hssembly is then to be placed in a protective enclosure
designed to permit visual observation of the test.
(c) The hose must be completely filled with water before testing.
(e) The disch .a.r~e nozzle shall be oriented in such a, manner that
optimum agent d~spersal can be effected.
(d) Pressure then is applied at a raie-of-pressure rise to reach the
test pressure within a minimum of one minute, The test pressure is
to be maintained for one fuU minute. Observations are then made to
note any distortion or leakage.
(f) If nozzle deflectors are installed, they shall be positioned to
obtain maximum benefit.
(e) If the test pressure has not dropped or if ~ e couplings have not
moved, the pressure is released. The hose assembly is then considered to have passed the hydrostatic test if no permanent distortion
has taken place.
(g) The discharge nozzles, piping, and mounting brackets shall be
installed in such a manner that they will not potentially cause injury
to personnel.
590
NFPA 12A
1. Agent shall not be discharged at head high or below, where
personnel in the normal work area could be injured by the agent
discharge.
'
A92 TCR
(h) Detectors shall not be located near obstructions or air
ventilation and'cooling equipment that would appredably affect their
response characteristics. Where applicable, air changes for the
protected area shall be taken into consideration. Refer to NFPA 72E,
?itandard on AutomaticFi~De~cto~, and the manufacturer's recommended guidelines concerning this area.
2. Agent shall not directly impinge off any loose objects or shelves,
cabinet tops, or similar surfaces where loose objects could be present
and become missiles.
(i) The detectors shall be installed in a professional manner and in
accordance with technical data regarding their installation.
(h) All agent storage containers shall be properly located in
accordance with an approved set of system drawings.
~) Manual pull stations shall be properly installed, readily
accessible, accurately identified, and properly protected to prevent
damage.
(i) All containers and mounting bra,_,ckets shall be securely fastened
in accordance with the manufacturer s requirements.
be~) Ifa discharge test is to be conducted, containers for the agent to
used shall be ~¢eighed before and after discharge. Fill weight of
container shall be verified by weighing or other approved methods.
(k) All manual stations used to release Halon shall require two
separate and distinct actions for operation. They shaU be properly
identified. Particular care shall be taken where manual release
devices for more than one system are in close proximity and could be
confused or the wrong system actuated. Manual stations in this
instance shall be clearly ident~ied as to which zone or suppression
area they affect.
(k) Adequate quantity of agent to produce the ¢tesired specified
concentration shall be provided. The actual room volumes shall be
checked against those indicated on the system drawings to ensure the
proper quantity of agent. Fan coastdown and damper closure time
shall be taken into consideration.
(I) For systems with amain/reserve capability, the main/reserve
switch shall be properly installed, readily accessible, and clearly
identified.
(1) The piping shall be pneumatically tested in a closed circuit for a
period of 10 minutes at 150 psig. At the end of 10 minutes, the
pressure drop shall not exceed20 percent of the test pressure.. When
pressurizing the piping, pressure shall be increased in 50 psi (3.5 bar)
increments.
(m) For systems using abort switcl~es, the switches shall be of the
deadman type requiringconstant manual pressure, properly
installed, readily access~le within the hazard area, and clearly
identified. Switches that remain in the abort position when released
shall not be used for this purpose. Manual pull stations shall always
override abort switches.
CAUTION:. Pneumatic pressure testing creates a potential risk
of injury to p.ersonnel in the area, as a result of airborne
projectiles, ff rupture of the piping system occurs. Prior to.
conducting the pneumatic pressure test, theprotected area
shall be evacuated and appropriate safeguards shall be
provided for test personnel.
in) The control unit shall be properly installed and readily
accessible.
4-7.2.4 (1-7.4.1.3(D)) Functional Testing.
Exception: The pr~ure te~t may be omitted if the total pi~ng contains no
more than one change in direction fitting between the storage container and the
discharge no~le, and where all piping is physically dmhed for tightness.
(a) Preliminary~unctional tests
/
1. If the system is connected to an alarm receiving office, the alarm
receiving office shall be notified that the system test is to be conducted and that an emergeKcy response by the fire department or
alarm station personnel is not desfred. Allconcerned personnel at
the end-user's facility shall be notified that a test is to be conducted
and instructed as to the sequence of operation.
(mi A pufftest with nitrogen shall be performed to check for
continuous piping.
4-7.2.2 (1-7.4.1.3(E)) Enclosure Integrity Acceptance. All total
flooding systems shall have the enclosure examined and tested to
locate and then effectively seal any significant air leaks that could
result in a failure of the enclosure tohold the specified Halon 1301
concentration level for the specified holding period. The currently
preferred method is using ablowef door fan unit and smoke pencil.
If quantitative results are recorded these could be useful for comparison at future tests. (See Appendix B).
2. Disable each agent storage container release mechanism so that
° activation of the release circmt will not release agent. Reconnect the
release circuit with a functional device in lieu of each agent storage
container release mechanism. For electrically actuated release
.
mechanisms, these devices may include 24-volt lamps, flash bulbs, or
circuit breakers. Pneumatically actuated release mechanisms may
include pressure gauges. Refer to the manufacturer's recommendations in all cases.
4-7.2.3 (1-7.4.1.3(c)) ElectricalAcceptance.
(a) All wiring systems shall be properly installed in compliance with
local codes, insurifig agencies, and the system drawings.
3. Check each detector for proper response.
(b) All field circuitry shall be measured for ground fault and short
circuit condition. When measuring field circuitry, all electronic
components (such as smoke and flame detectors or special electronic ,
equipment for other detectors or their mounting bases) shall be
'
removed and jumpers properly installed to prevent the possibility of
damage within these devices. Replace components afteimeasuring.
4. Check that polarity has been observed on all polarized alarm
devices and auxiliary relays.
5. Check that all end.of-line resistors have been installed across the
detection and alarm bell circuits where required.
6. All supervised circuits shall be checked for proper trouble
response.
(c) Power shall be supplied to the control unit from a separate
dedicated source whichwill not be shut down on system operation.
(b) System functional operational test
(d) Adequate and reliable primary and 24-hour minimum standby
sources of energy shall be used to provide for operation of the.detection,
signaling, control, and actuation requirements of the system.
1. Operate detection initiating circuit(s). All alarm functions shall
occur according to the design specification.
(e) All auxiliary functions such as alarm sounding or displaying
devices, remote annunciators, air handling shutdown, power
shutdown, shall be checked for proper operation in accordance with
system requirements and design specifications. If possible, all airhandling and power-cutoffcontrols shall be of the type that once
interrupted require ma-gual restart to restore power.
9. Operate the necessary circuit to initiate a second alarm circuit.
Verify fill second alarm functions occur according to design specifications.
3. Operate manual release. Verify that manual release functions
occur according to design specifications.
'(0 Silencing of alarms (if desirable) shall not affect other auxiliary
functions such as air handling or power-cut off ffrequired in the
design specification.
4. If supplied, operate abort switch circuit. Verify that abort
functions occur according to design specifications. Confirm that
visual and audible supervisory signals are received at the control
panel.
(g) The detection devices shall be checked for proper type and
location as specified on the system drawings.
591
t
NFPA 12A - - A92 TCR
5-1.2.5 ULC Pubfications. Underwriters Laboratories of Canada, 7
Crouse Road, Scarborough, Ontario, Canada M1R 3A9.
5. All automatic valves shall be tested unless testing the valve will
release Halon or damage the valve (destrnctlve testing).
ULC $524-M86, Standard for the Installation of Fire Alarm Systems
6. Where 'required, pneumatic equipment shall be checked for
integrity to assure proper operation.
ULC $529-M87, Smoke DetectorJfor Fire Alarm Systems
(c) Testing of remote monitoring operations, ifapplicable
5.1.2.6 CGA Publications. Compressed Gas Association, 1235
Jefferson Davis Highway, Arfngton, VA 22202.
I. Operate one of each type of input device while on standby
power. Verify that an alarm signalis received at remote panel after
device is operated. Reconnect primary power supply•
CGA C,6-1984, Standard/or Irtmal lnspeaion of Compr~at Gas Cylinders
(s~o
2. Operate each type of alarm condition on each signal circuitand
verifyreceipt of trouble condition at the remote station.
5.1.2.7 US Government Publication. SuperintendentofDocuments,
US Government Printing Office, Washington, DC 20401.
(d) Testing of the control panel primary power source
Cod, ofFederalRegulations, Title 49 Transportation, Parts 170-190.
1. Verify that the control panel is connected to a dedicated circuit
and labeled properly. This panel shallbe readilyaccessible,yet
restrictedto unauthorized personnel.
This A [ ~ d i x is not apart of the refuiremmts of this 2~FPA do~meng but
is included for information purposes only.
2. A primal_ power failureshallbe tested in accordance with the
manufacturer s specification with the system fully operated on
standby power for the required design period.
(e) When all functional testing is completed, reconnect each agent
storage container so that activataon of the release circuit will release
the agent. System shall be returned to its fully operational design
condition.
(f) Tests shall be in accordance with the appropriate NFPA or
Canadian standards.
Chapter 5 Referenced Publications
5-1 The following documents or portions thereof are referenced
within this standard and shall be considered part of the requirements
of this document. The edition indicated for each reference is the
current edition as of the date of the NFPA issuance of this document.
5.1.1 NFPA Publications. National Fire Protection Association, 1
Batterymarch Park, P.O. Box 9101, Quincy, MA 02269-9101.
NFPA 70, NationalElectrical Code, 1990 edition
NFPA 72, Standard for the Installation, Maintenance, and Use of Protective
Signaling Systems, 1990 edition
NFPA 72E, Standard on Automatic Fire Detectors, 1990 edition
AppendixA
A-1-$.1 Normally Occupied Area. Spaces occasionally visited by
personnel, such as transformer bays, switch.houses, pump rboms,
vaults, engine test stands, cable trays, and tunnels, microwave relay
stations, flammable liquid storage areas, enclosed energy's~tems,
etc., are examples of areas considered not normally occupled.
A-I-4.1 Halogenated Extingut~hlnc, Agents. A halogenated compound is one that contains one or'more atoms of an element from
the halogen series: fluorine, chlorine, bromine, and iodine. When
hydrogen atoms in a hydrocarbon compound, such as methane
(CHa) or ethane (CHiCHi), are replaced with halogen atoms, the
chen~ical and physical~rolYerties of the resulting compound are
markedly changed. Methane, for example, is a light, flammable gas.
Carbon tetrafluoride (CF~), also a gas, as chemically inert, nonflammable, and extremely inw~in toxicity. Carbon tetrachloride (CCI~) is
a volatile liquid that is not only nonflammable, hut was widely used
for manyyears as a fire extinguishing agent in spite of its rather high
toxicity. Carbon tetrahromide (CBra) and carbon tetralodide (CIa)
are solids that decompose easily under heat. Generally, the ~reser~ce
of fluorine in the compound increases its inertness and stability;, the
presence of other halogens, particularly bromine, increases the fire
extinguishing effectiveness of the compound. Although a very large
number of halogenated compgunds exist, only the fol]owlng five have
been used to a significant exteht as fire extinguishing agents:
0
Halon I01 I, hromochloromethane, CHsBrCI
,5.1.2 Other Publications.
Halon 121 I, bromochlorodifluoromethane, CBrCIFs
5.1.2.1 ANSI Publications. American National Standards Institute,
Inc., 1430 Broadway, New York, NY 10018.
Halon 1202, dihromodifluoromethane, CBrzF,
Halon 1301, bromotrifluoromethane, CBrFs
ANSI B1.20.1-1983, Standard for Pipe Threads, GeneralPurpose
Halon 2402, dihromotetrafluoroethane, CBrFtCBrF2
ANSI B31.1-1986, PowerPiping Code
5.1.2.2 ASTM Publications. American Society for Testing and
Materials, 1916 Race Street, Philadelphia, PA 19103.
ASTM A53..88, Spedfications for Welded and SeamlessSteel Pipe
ASTM A106-88, Specificationsfor Seamless Carbon SteelPipefor High
Temperature Service
ASTM A120-84, Specificationsfor Welded and SeamlessSteel Pipe
Halon Nomenclature System. The Halon system for naming
halogenated hydrocarbons was devised by the U.S. Army Corps of '
Engineers to provide a convenient and quick means of reference to
candidate fire extinguishing agenu. The first digit in the number
represents the number of carbon atoms in the compound molecule;
the second digit, the number of fluorine atoms; the third digit, the
number of chlorine atoms; the fourth digit, the number of bromine
atoms; and the fifthdigit,the number of iodine atoms. Terminal
zeros are dropped. Valence requirements not accounted for are
assumed to behydrogen atoms (number of hydrogen atoms = Ist
digittimes 2, plus 2, minus the sum of the remalnmg digits).
ASTM B88-88, spedfications for Seamless Copper Water Tube
ASTM E380-86, Standard for Metric Practi~
Halon 1301. Halon 1301 chemically isbromotrifluoromethane,
CBrF.. Itscumbersome chemical name is often shortened to
" b r o m o m or even further to "BT. The c o m p o u n d asused as a lowtemperature refrigerantand as a cryogenic fluid,as well as a fire
extinguishing agent.
.is
5.1.2.3 ASME publication. American Society of Mechanical
Engineers, 345 East 47th Street, New York, NY 10017.
ASME Boiler and Pressure VesselCode 1986.
5-1.2.4 CSAPublications. Canadian Standards Association, 178
Rexdale Boulevard, Rexdale, Ontario, Canada M9W 1R3.
CAN3-Z234.1-89, Canadian Metric Practice Guide
tt
•
Physical Properties. A listof important physical properties of Halon
1301 isgiven in Table A-I-4.1. Under normal conditions, Halon 1301
isa colorless,odoriess gas with a density approximately 5 times that of
air. It can be liquefiedupon compression for convenient shipping
and storage. Unlike carbon dioxide, Halon 1301 cannot be solidified
at temperatures above -270"F (-167.80C).
C22.1-1986, Canadian Elect~cal Code, Part I.
592
I
NFPA 1 2 A - A92 TCR
The "ionic" theory supposes that the uninhibited combustion process
includes a step in that O¢ions are formed by the capture of electrons that
come from ionization of hydrocarbon molecules. Since bromine atoms
have a much higher cross section for the capture of slow electrons than
O., the bromine inhibits the reaction by removing the electrons that are
ne~eded for activation of the oxygen.
T h e variation of vapor pressure with temperature for Halon 1301 is
shown in Figures A-I-4.1 (a) and (b). As the temperature is increased,
the vapor pressure and vapor density increase and the liquid density
decreases, until the critical temperature of 152.6°F (67°C) is reached.
At this point, the densities of the liquid and yapor phases become
equal and the liquid phase ceases to exist. Above the critical
temperature, the material behaves as a gas, but it can no longer be
liquefied at any pressure.
A-IA.2.5 General Information on Total Flooding S y ~ m s .
From a performance viewpoint, a total flooding system is designed to
develop a concentration of Halon 1301 that will extinguish fires in
combustible materials located in an enclosed space. It must also
maintain an effective concentration until the maximum temperature
has been reduced below the reignition point.
Fire "Ext~ndshment Characteristics. Halon 1301 is an effective fire
extin~uishing agent that can be used on many types of fires. It is
effecuve in extinguishing surface fires, such as flammable liquids, and
on most solid combustible materials except for a few active metals
and metal hydrides, and materials that contain their own oxidizer,
such as ceUuiose nitrate, gunpowder, etc.' "
..
The concentration'of Halon 1301 required will depend on the type
of combustible material involved. This has been determined for
many surface-type fires, particularly those involving liquids and gases.
For dee l>:seated fires, the critical concentration required for
extingntshment is less definite and has, in general,been established
by practical test work.
Exllngnlshlng Mechanism. The mechanism by which Halon 1301
extinguishes fires is not thoroughly known; neither is the combustion
process of the fire itself. It appears, however, to be a physiochemical
inhibition of the combustion reaction. Halon 1301 has also been
referred to as a "chain breaking" agent, meaning that it acts to break
the chain reaction of the combustion process. Halon 1301 dissociates
in the flame into two radicals:
It is important that an effective agent concentration not only be
achievedbut that it be maintainedfor a sufficient period of ume to
allow effective emergency action by trainedpersonnel. This is equaliy
important for all classes of fires since a perststent ignition source
(e.g., an arc, heat source, oxyacetylene torch, or "deep-seated" fire)
can lead to a recurrence of the inuial event once the agent has
dissipated. Halon 1301 extinguishing systems normally provide
protection for a period of minutes but are exceptionally-effective for
certain applications. Water supplies for standard sprinklers, on the
other hand, are normally designed .to provide protection for an
extended period of time. The designer, buyer, and emergency force
in p.articular need to ,closel.~y review the.advanta,g.es and limitauons of
avatlable systems as appliedto the specific m u a u o n at hand, the
residual risks being assumed, and tile proper emergency procedures.
CBrF~ -- CF3 + Br
Two inhibiting mechanisms have been proposed, one that is based
on a free radical process, and another based on ionic activation of
o.xygen during combustion.
The "free radical" theory supposes that the bromide radical reacts
with.the fuel to give hydrogenbromide,
R - H + Br. -- R- + H B r
The discharge of minimum extinguishing concentration of Halon
1301 into enclosures containing operating diesel engines not drawing
combustion air from outside the space creates a special problem•
Experience has shown the engine will continue to operate resulting
in a decrease in agent concentration and extensive decomposition of
the Halon.
which then reacts with active hydroxyl radicals in the reaction zone:
H B r + O H . ~ H 2 0 + Br.
The bromide radical again reacts with more fuel, and so on, with the
result that active H, * OH, * and O: radicals are removed, and less
reactive alkyl radicals are produced.
Figure A-1-4.1(a) Vapor pressure of Halon 1301 vs. temperature.
I
CO0
bJ
I
td
D
(n
/- J
150
80
-
,I
f
60
z
J
CRITICAL POINT
152.6 °F,, S 6 0 . :) P S I G
f
I
./
,v, w I 0 0
Oa:
o.<
/,
/
• •
j" i
#,A
O-
/
0
O.
J
.
,15
.t 0
-eo
~r
/
J
. -40
-20
20
40
60
TI:M pF'RATUR E
593
80
-e F
I00
120
140
160
Z
NFPA 12A -- A92 TCR"
:N
1301
VAPOR PRESSURE OF HALON
HA
vs.
TEMPERATURE
4.0
=
2C
0
"
lfl
ev,
eY
e~
-7
e~
-40
-20
0
20
TEMPERATURE, °C
40
60
80
Figure A-1-4.1 (b) (Metric.)
Table A-I-4.1 Physical Properties of Halon 1301
British
Molecular weight
Boiling point at 1 atm.
Freezing point
Critical temperature
Critical pressure
Critical volume
Critical density
Specific heat, liquid,
at 77°F (25°C)
Specific heat, vapor, at constant pressure (1 atm.) and 77°F (25°C)
Heat of vaporization at
boiling point
Thermal conduct,vity of liquid at 77°F
(25°C)
Viscomy. liqmd, at
77°F (25°C)
V~scosJty. vapor, at
77°F (25°C)
Surface tensmn at 77°F (25°C)
Refractive index of liquid at 77°F (25°C)
1.238
Relative dlelecmc strength at 1 a t m ,
77°F (25°C) (nitrogen = l.O0)
Solubility, of Halon 1301 m water at I
a t m . 77°F (25°C)
Solubdlty of water m Halon 1301 at
70°F (21°C)
'.
148.93
-71.95°F
-270°F
152.6°F
575 psia
0.0215 ft3/Ib
46.5 Ib/ft 3
SI
148.93
-57.75°C
- 168°C
67.0°C
39,6 bar
0,000 276 ma/kg
745 kg/m a
0.208 BTU/Ib-°F
870 J/Kg-°C
0.112 BTU/Ib-°F
469 J/Kg-°C
51.08 BTU/Ib
118.8 kJ/kg
0.024 BTU/hr-ft-°F
0.85 W/m-°K
1.01 x 10-4 Ib/ft-sec
1.59x 10-4 Poiseuille
• 1.08x 10-s Ib/fi-sec
4 Dynes/cm
1.238
1.63x 10-5 Poiseuille
0.004 N/m
1.238
1.83
1.83
0.03f7~ by wt
0.03~ by wt
0 0095% by wt
0.0095% by wt
A-l-5.1 Hazards to Personnel. The discharge of Ha/on 1301 to
exdnguish a fire may create a hazard to personnel from the natural
Ha/on 1301 itself and from theproducts ofdecomposidon that result
from exposure of the agent to the fire or other hot surfaces.
Exposure to the natural agent is generally of less concern than is
exposure to the decomposidon products. However, unnecessary
exposure of personnel to either the natural agent or to the decomposiuon products should be avoided.
(a) Noise. Discharge of a system can cause noise loud enough to be
startling but ordinarily insufficient to cause traumatic injury.
(b) Turbulence. High velocity discharge from nozzles may be
sufficient to dislodge substantial objects or injure people direcdy in
the path. SDtem discharge may also cause enough general turbulence in the enclosures to move unsecured paper and light objects.
(c) Cold Temperature. Direct contact with the vaporizing liquid
being discharged from a Ha/on 1301 system will have a strongchiMng
effect on objects and can cause frostbite burns to the skin. The liquid
Other potential hazards to be considered for individual systems are:
594
NFPA 12A
A92 TCR
In many experimental studies on humans, no subject has ever had a
serious arrh~hmia at Halon 1301 leveh below 10 percent. One
arrhythmia has been observed at a 14-percent level after a few minutes'
exposure~but the subject reverted to a normal r h y h m upon r e r ~
to
fresh airy In recent studies at the Medical College of Wisconsin ,
exposure to Halon 1301 up to 7.1 percent for 30 minutes did not produce
sugicient adverse effects to harm, confuse, or debilitate human subjects or
Lrevent them from performing simple mechanical tasks, following
tructions, or exiting from the Halon 1301 exposure area. In addition,
these subjects experienced no significant EKG or EEG abnormalities
during or afterexposure.
phase vaporizes .rapidlywhen mixed with airand thus limits the hazard to
the immediate vicinity of the'discharge point. In humid atmospheres,
minor reduction in visibility may occur for a bri'efperiod due to the
condensation of water vapor.
Natural or Undecompo~.. Halon 1301..When Halon 1301 is used in
systems designed and installed according to this NTPA standard, risk to
exposed individuals is minimal. Its toxicity is very low in both animals and
humans. The main physiologic actions of Halon 1301 at high inhaled
levels are central nervous system (CNS) depression and c a r d i o ~ a r
effects.
Itisconsidered good practiceto avoid allunnecessary exposure to Halon
1301 and to limitexposures to the followingtimes:
AnLmal~ Halon 1301 has a 15-n~Linuteapproximate lethal concentration
(ALC) of 83 percent (0o added) *, suggesting a very low degree of acute
inhalation toxicity. In rflonkeysand dogs, mil-.dCNS effects occur after a
few minutes exposure above 10 percent,progressingto lethargy in
2
monkeys and tremors and convulsion in dogs at leyels above 20 percent.
7 percent and below- 15 minutes
7-10 percent- 1 minute "
10-15 percent- 30 seconds
Above 15 percent- prevent exposure
Spontaneous effects on blood pressure and cardiac rhythm occur at
much,2higher levels, approximately 20 percent and 40 percent, respectively.
.~m~nY~llanesuffering from the toxic effects of Halon 1301 vapors should
tely move or be moved to fresh air. In treating persons suffering
toxic effects due to exposure to this agent, the use of epinephrine
(adrenaline) and similar drugs must be avoided because they may
produce cardiac arrhythmias, including ventricular fibrillation.
It has also been known since the early 1900s that the inhalation of many
halocarbons and hydrocarbons, like carbon tetrachloride and hexane, can
make the heart abnormally sensitive to elevated adrenalin levels, resulting
in cardiac arrhythmia and possihly death. This phenomenon has been
referred to as cardiac sensitization. Halon 1301 can also sensitiz~ the
heart, but only at high inhaled leveh. For example, in standard cardiac
sensitization screening studies in dogs using5-mmute exposures and large
doses of injected a3drenalin, the threshold for sensitization is in the 7.5 to
10 percent range.
Halon 1301 is colorless and odorless. Discharge of the ;igent may create
a light mist in the vicinity of the discharge nozzle, resulting from
condensation of moisture in the air, but the mist rarely persists after
discharge is completed. Thus, little hazard is created from the standpoint
of reduced visibility. Once discharged into an enclosure, it is dlmcult to
detect its presence through normal human senses; in concentrations
above approximately 3 percent, voice characteristics are changed due to
the increased density of the agent/air mixture.
•
"
In other studies on dogs, a certain critical blood level was a.Ssodated with
inspired levels needed to sensitize the heart. With exposure to Halon
1301, a relatively insoluble fluorocarbon, blood concentrations rise
rapidly, equilibrate within 5-10 minutes, and fallyapidiy upon cessation of
exposure. There is no accumulation of Halon 1301 as indicated by similar
blood concentration at 5-10 minutes and at 60 minutes of exposure.
When dogs exposed to Halon 1801 for 60 minutes are given a large dose
of adrenalin, the threshold for cardiac sensitization remains the same as
for 5-minute ex~. sures ~ 7.5 to 10.0 percent. In addition, studies have
shown that sensitization is only a temporary effect, since adrenalin
injections given 10 minutes after exposure to known sensitizing levels have
not resulted in a r r h y t h ~" , .*
.
•
*
.
°
'
1
•
In total flooding systems, the high density of Hal on 1301 vapor (5 times
that of air) requires the use of discharge nozzles that will achieve a weLL
mixed aunosphere to avoid local pockets of higher concentration. Once
mixed into the air, ~ e agent will not settle out.
Decomposition Products of Halon 1301. Although Halon 1301 vapor
has a low toxicity, its decomposition products can be hazardous. Tlie most
accepted theory is that the ~j~or must decompo_se before Halon 1301 can
inhibit the combustion reacuons (s~A-1-5.2). The decomposition takes
place on exposure to a flame, or to a hot surface at above approximately
900°F (482°C). In the presence of available hydrogen (from water vapor,
or the combustion process itself), the main decomposition products are
the halogen acids (I-IF, HBr) and free halogens (Brg) with small amounts
of carbonyl halides (COFs, COBrs).
,
All percentage levels m this sectmn refer to volumetric concentmuons of
Halon 1301 in air.
• See G1.6 for references.
The decomposition products of Halon 1301 have a characteristic sharp,
acrid odor, even in minute concentrations of only a few Em'ts per million.
This characteristic provides a built-in warning system for the agent, but at
the same time creates a noxious, irritating atmosphere for those who must
enter the hazard following the fire.
Using the standard cardiac sensitization test protocol and large doses of
adrenalin, dogs with experimentally induced myocardial infarction were
tested to determine whether this type of heart con~tion might significan@ lower the threshold for cardiac sensitization. Results on Halon
1301 showed no greater potential for cardiac sensitization among dogs
ha.vin~ recovered from myocardial infarction than for normal, healthy
a n l m R l $ .
•
The amount of Halon 1301 that can be expected to decompose in
"extinguishing a fire depends to a large extent on the size of the fire, the
concentration of Halon vapor, and the length of time that the agent is in
contact with flame or heated surfaces above 90&F (482°C). If'there is a
very rapid buildup of concentration to the critical value, then the fire will
be extinguished quickly, and there will be little decomposition. The
actual concentranon of the decomposition products must then depend
on the volume of the room in which the fire was burning, and on the
degree o~ mixing and ventilation. For example,:~xlingnishment ofa 25-sq
ft (2.3-m) heptane fire in a 10,000.cu ft (283-m) enclosure within 0.5
seconds produced only 12 ppm I-IF. A similar test having an extinguishment tL,ne of 10 seconds produced an average I-IF level of 950 ppm over a
9-minute period.
"
Halon 1301 has also been tested for mutagenic and teratogenic effects.
In a standard 48-hour Ames Test at levels of 40 percent, no evidence of
mutagenidty was seen in Salmonella typhimurium bacteria with or
without metabolic activation. Pregnant rats exposed to Halon 1301 at
levels as high as 5 percent exhibited no embryotoxic or teratogenic effects.
• The preceding animal studies show that Halon 1301 is very low in
toxicity. Although high inhaled levels can affect the CNS and cardiovascular system, such effects are mpidiy and completely reversible upon
. removal from exposure, if the exposure conditions were not severe
enough to prodtice death.
--
Clearly,longer exposure of the vapor to temperatures in excessof 900°F
(482°C) would produce greaterconcentrationsof these gases, The type
and sensitivityo~'detection,coupled with the rate of discharge,should be
selectedto minimize the exposure time of the vapors to the elevated
temperature ifthe concentration of breakdown products must be '
minunized. In most casesthe area would be untenable for human
occupancy due to the heat and breakdown products of the fireitself.
A-1-5.1.2 Safety Requiremenm. The steps and safeguards necessary to
prevent injmy or death to personnel in areas whose atmospheres will be
made hazardous by the dishharge or thermal decomposition of Halon
1301 may include the following:
-
HumanL The very low toxidty of Halon 1301 in animal studies has been
.confirmed by over 20 years of safe manufacture and use. There has never
been a death or any permanent injury assodated with exposure to Halon
1301.
Exposure to Halon 1301 in the 5 to 7 percent range produces little if
any, noticeable effect. At levels between 7 and 10 percent mild CNS '
effects such as dizziness and tingling in the extremities have been
reported. Above 10 percent, some subjects report a feeling of impending
unconsciousness after a few minutes, although test subjects ex~posedup to
14 percent for 5 minutes have not actually lost consciousness. These
types of CNS effects were completely reversible upon removal from
exposure.
(a) Provision of adequate alsleways and routes of exit and keeping them
dear at all times.
595.
I
.,
NFPA 12A - - A 9 2 TCR
(b) Provision of emergency lighting and directional signs as necessary to
ensure quick, safe evacuation.
nitrogen to Halon 1301 storage containers to pressurize the agent above
the v'apor pressure, called s"-u~'pressurizing," will prevent the- container
pressure from decreasing so drasiicah~ at low temperatures.
(c) Provisionof alarms within such areas thatwiU operate immediately
upon detection of the fire.
Su[.xwpressurizadon causes some of the nitrogen to permeate the liquid
_poruon of the Halon 1301. This "solubility" is related both to the degree
of superpres`mHzation and to temperature as follows:
(d) Provisionof only outward-swinging, self-closingdoors at exitsfrom
hazardous areas,and, where such doors are latched,provisionof panic
hardware.
X.,
(e) Provision of continuous alarms at entrances to such areas until the
atmosphere has been restored to normal
Where:
(f) Provisionofwamingand instructionsignsat enwances to and inside
such areas. These signs should inform persons in or entering the
protected area that a~Halon 1301 system is installed, and may contain
additional instructions pertinent to the conditions of the hazard.
_I-Ix = Henry's Law constant, psi (bars) per mole fraction.
P,-= ~
pressure of nitrogen above solution, psi (bars).
X~ = Nitrogen concenwafion in liquid Halon 1301, mole fizction.
(g) Provision for prompt discovery and rescue of persons rendered
unconscious in such areas. This may be accomplished by having such
areas searched immediately by trained personnel equipped with proper
breathingequipment. Serf-contained breathing~ equipment and
personnel trained in its use, and in rescue pracuces, including artificial
respiration, should be readily available.
Nitrogen partial premxtre may be calculated from the total pressure of
the system and the vapor pressure of Halon 1301 (Figure A-l-4.1 (a) & (b))
as follows
(h) Provision of instruction and drills for all personnel within or in the
vicinity of such areas, including maintenance or construction people who
may be brought into the area, to ensure their correct action when Halon
1301 protective equipment operates,
'
•
Where:
(i) Provision of means for prompt ventilation of such areas. Forced
ventilation will often be necessary. Care should be taken to ready dissipate
hazardous atmospheres and not merely move them to another location.
Halon 1301 is heavier than air.
(bars).
P,
= P - (l
- X,)Pv
P = Total pressure of system, psi absolute (psi gage + 14.696) (bars).
Pv= VaP°r pressure of Halon 1301, psi absolute (psl gage + 14.696)
.Hgure .4.-2-1.4.1(a)&(b) shows that vatiadon of Hemy's Law constant, Fix,
wire temperature.
Isometric diagrams for Halon 1301 superpressurized with nitrogen,
Figures A-2-1.4.1(c) (360 psi~) and A-2-1.4.1(d) (600 psig), show the
relationship of storage container pressure vs. temperature with lines 0£
constant filldensity.
(j) Prohibition against smoking by persons until the atmosphere has
Ixen purged of Halon 1301.'
(k) Provision of such other steps and safeguards that a careful study of
each partidtiar situation indicates is necessary to prevent injury or death.
These curvesdemonstrate the danger in overfillingcontainerswith
Halon 1301. A container filledcompletelywith Halon 1301 at 70°F
(21°C) and filledto 97.8 Ib/cu R (1566 kg/m s) and _~bsequently
superpressurlzed to 600 pslg (42.38 bars) would develop apressure of
3000 pslg (207.86 bars) when heated to 130°F (54°C); iffilledto 70 Ib/cu
ft (1121 kg/m s) or,lessas permitted in thisstandard, a pressm'e of 1040
pslg (72.72 bars) would be developed. The same prindples apply to liquid
Halon 1301 thatbecomes trapped between two valvesin pipelines,
Adequate pressure relief should alwaysbe provided in such situations,
A-1-5.2 The minimum clearances listed in Table 1-5.2 are for the purpose
of electrical clearance under normal conditions; they are not intended for
use as "safe"distances during fixed Halon 1301 system operation.
The clearancesare based on minimum general practicesrelatedto
design Basic InsulationLevel (BIL) values.-To coordinate the required
clearance with the electricaldesign, the design BIL of the equipment
being protected shall be used as a basis, although this is not material at
nominal line voltages of 161 kv or less.
5500
Up to electrical system voltages of 161 kv, the design BIL kv and
corresponding minimum clearances, phase to ground, have been
established through long usage.
At voltages higher than 161 kv, uniformityin the relationship between
• design BIL kv and the various electrical system voltages has not been
established in practice. For these higher system voltages it has become
common practice to use BIL levelsdependent on the degree of protection
to be obtained. For example, in 230-kv systems, BILs of 1050, 900, 825,
750 and 650 kv have been utilized.
5000
J
f-
Required clearance to ground may also be affected by switching surge
duty, a power system desgn factor that, along with BIL, must correlate
with selected minimum clearances. Electrical design engineers'may be
able to furnish dearances dictated by switching surge duty. Table 1-5.2
deals only with clearances required by design BIL
0
|IN
4500
\
t
\
\
4000
A-2-1A.1 Storage Containers. Storage containers for Halon 1301 must be
capable of withstanding the total pressure exerted by the Halon 1301
vapor plus the nitrogen partial pressure, at the maximum temperature
contemplated in use. Generally, steel cylinders meeting US Department
of Transportation requirements will be used. Manifolded cylinders are
used forhrge instaUations`
\
o
\
3500
\
Each container must be equipped with a discharge valve capable of
dischar~ng liquid Halon 130I at the required rate. Containers with toE'_
mounted v~¢ds require an internal dip robe extending to the bottom of
the cylinder to permit discharge of liquid phase Halon 1301.
3000
Nitrogen Superptmmalzation. Although the 199 psig (14.73 bars) vapor
pressure of Halon 1301 at 70°F (21°C) is adequate to expel the contents
of the storage containers, this pressure decreases rapidly with temperature. At 0°F (-18°C), for example, the vapor pressure is 56.6 psig (4.92
bars), and at-40°F (-40°C) it is only 17.2 l~ig (2.20 bars). The addition of
-40
-20
0
20
40
60
80
I00
TEMPERATUR( D °F
120
140
160
Figure A-2-1.4.1(a) Henry's law constant for nitrogen solubility in ,quid
halon 1301.
596
I
NFPA 12A
-
A92 TCR
-
350
-200
v /
F
J
f
F
~m
I I /
I/J
"\
J
~lJ
\
\
LL
3oc
"1~
ISOMETRIC DIAGRAM
HALON 1301 PRESSURIZED TO 424
BARS AT 21 °C
\
"',
/ ~"Z ~
_
f--
I~o'/!/
o ~ / '///"//
-
<
I-
~
'
I/
1 J
/i
c. / /
\
//~'/,
_=
o
\
/Z'/
A //~
' / z ,'/
L 'llJ
100
I/~ '///
,///~,/
L'~F
HENRY'S LAW CONSTANT
FOR NITROGEN
SOLUBILITY
IN L I Q U I D H A L O N 1301 -
0
~,1
~c~
m
\
250
/J
I n n
.>.
n"
k
l
i
i
l
i
n
|
n
~
|
f
R
Cntmal Point- /
C
-20
200
-40
-20
20
0
40
80
60
TEMPERATURE, °(3
/
/,
/ r
//
/ / ,
/
//
/
/ , /,
/////,
/
/
~'h // //
IIJ //
3////
h///, r
I/Z g /
,.
/~ ~ ' /
Iv
• I
/
/
~ f
-20
0
I
50
100
~
100
150
A-2-2.1.1 The following presents calculations to provide minimum pipe
schedules (wall thickness) for use ,with both ~o0..l~i and 600 psi Halon
1301 fire extinguishing ~tems,in accordance wlth this standard.
Paragraph 2-2.1.I requires that "the ~ . wall shall be calo~|~t_,~:Iin
accordance with ANSI B31.1, PowerPiplng Code."
"//
/,
-
Figure A-2-1.4.1(d) (Metric)
Although Halon systems are not mbjected to continuous pressurization,
some provisions should be made to ensure that the type o f piping installed
can wtthstand the maximum stress at maximum storage temper'am.re& ,
Max~urn allowable stress levels for this condition should be established
at values of 90 percent of the minimum yield strength or 50 percent of the
minimum tensile strength, whichever is less, Alljoint factors-shduld be
applied after this value is determined. ;
200
~//
50
TEMPERATURE, °C
Figure A-2-1.4.1(b). (Metric.)
ISOMETRIC DIAGRAM
HALON 1301 PRESSURIZED TO 258
BARS AT 21 °C
0
150
TEMPERATURE, °C
Figure A-2-1.4.1(C) (Metric) Isometric diagram. Halon 1301
pressurized to 360 psig at 70 ° F.
,
.4,-2-2.1 Piping. Piping should be installed in accordance with good
commeraal practice. Care should be taken to avoid possible resuictions
due to foreign matter, faulty fabrication, or improper installation.
The piping system should be securely supported with due allowance for
agent thrust forces; thermal ~ o n
and contraction, and should not be
subjected to mechanical, chemacal, vibration, or other damage. ANSI ]331.1
should be consulted for guidance on this matter. Where explosions are
597
NFPA 12A - - A 9 2 T C R
0
Inn
200
300
Temger~um.°F
Figure A-2-1.4.1(c) Isometric diagram.°
Halon 1301 pressurized to 360 psig at 70 F.
'Minimum Piping Requirements for Halon 130'1 Systems
(b) The calculations apply only to steel pipe conforming to ASTIVlA-63
or A S T M A-106, and copper tubing conforming to A S T M B.88;and
360 psi and 600 psi Charging Pressure
(c) The calculationscover threaded, welded, and grooved jointsfor
steelpipe; and compression fittingsfor copper tubing.
1. Limitations on piping to be used for Halon systems (or any
pressurized fluid) are set by:'
3. The basic equadon to find the minimum wall thickness for piping
under internal pressure is:
(a) Maximum pressure expected within the pipe;
(b) Material of construction of the pipe, tensile strength of the
material, yield strength of the material, and temperature limitations
of the material;
t = [PD/2SE]
(c) Joining methods, i.e., threaded, welded, grooved, etc.;
Where:
(d) Pipe construction method, i.e., seamless, ERW (electric
resistance welded), furnace welded, etc.;
t
D
P
SE
A
(e) Pipe diameter; and
(0 Wall thickness of the pipe.
+
=
required wall thickness (inches)
outside pipe diameter (inches)
= . maximum allowable pressure (psi)
maximum allowable stress [indudingjoint eflidency] (psi)
= allowance for threading, grooving, etc. (inches)
NOTE: for these calculations
2. The calculations are based on the following:
A
A
A
A
(a) The minimum calculated pressure is 1000 psi for systems using
an initial charging pressure of g00 psi, and 620 psi for systems using
an initial charging pressure of 360 psi;
598
= depth of thread for threaded connections
= depth of groove for cut groove connections
ffi zero for welded or rolled groove connections
= zero for joints in copper tubing using compression fittings.
NFPA 12A -- A92 TCR
i
:2
Isometric Dlll~Clm
-qalon 1301 Prellunzed to
600 PSIG at 7 0 ° F
0
100
300
200
Temperature, °F
Figure A-2-1.4.1(d) Isometric diagram.
Halon 1301 pressurized to 600 psig at 70°F.
,The term SE is defined as 1/4 of the tensile strength of the piping
material or 2/3 of the yield strength (whichever is Iower) multiplied
by a joint efficiency factor.
Joint effidency factors are:
i.0 for seamless
0.85 for ERW (Electric resistance welded)
0.60 for furnace butt weld (continuous weld) (Class F)
4. The foilowing listing gives values for SE as taken from Appendix
A of the ASME/ANSI Code for Pressure Piping (ASME/ANSI B31).
Identical values are given in ASME/ANSI ]331.1 (Power Piping) and
ASME/ANSI 31.9 (Building Service'sPiping).
SEValue
G r a d e C Seamless Pipe
G r a d e B Seamless Pipe
G r a d e B Seamless Pipe
G r a d e A Seamless Pipe
G r a d e A Seamless Pipe
G r a d e B E R W Pipe
G r a d e A E R W Pipe
Class F F u r n a c e W e l d e d
Pipe
Seamless C o p p e r T u b i n g
• (Annealed)
Seamless C o p p e r T u b i n g
"(Drawn)
A S T M " A - 106
A S T M A-53
A S T M A-106
A S T M A-53
A S T M A- 106
A S T M A-53
A S T M A-53
17500
15000
15000
12000
12000
12800
10200
psi
psi
psi
psi
psi
psi
psi
' A S T M A-53
6800 psi
A S T M B-88
5100 psi
A S T M B-88
9000 psi
5, The basic equation can be rewritten to solve for P so as to
determine the maximum allo/eable pressure for which a pipe of
thickness t can be used:
P = 2SE (t - A ) / D
599
NFPA 12A -- A92 TCR
As required by 2-2.1.1 of this standard, for systems having a charging
pressure of 360 psi, the calculated pressure (P) must be equal to or
greater than 62Opsi.
Min!rnum Piping Requirements '
Haloa 1801 Systems - - $60 p,d .Charging Pressure
Steel Pape--Threaded Connecnons
For systems having a charging pressure of 600 psi, the calculated
• pressure (P) must be equalto or greater than 1000 psi.
ASTM
ASTM
ASTM
ASTM
ASTM
ASTM
These pressure values are based on a maximum agent storage
temperature of 130°F.
6. If higher storage temperatures are approved for a given system,
the internal pressure should be adjusted to the maximum internal
Palressure at maximum temperature. In performing this calculation,
l joint factors and threading, grooving, or welding allowances
should be taken into account.
A-106 Seamless, Grade C
Schedule 40--% m thru
A-106/A-53 Seamless, Grade B Schedule 40--% in thru
A-106/A-53 Seamless, Grade A Schedule 40--% an thru
A-53 E R W Grade B
Schedule 40--% m thru
A-53 E R W Grade A
Schedule 40--% an thru
A-53 Furnace Weld Class F
Schedule 40--% m .thru
Schedule 80--2 an. thru
Steel Pipe--Welded or Roiled Groove ConnecUons
ASTM
ASTM
ASTM
ASTM
ASTM
ASTM
7. Paragraph 102.2,4(B) of the Power PipingCode (ASME/ANSI
B31.1) allows the maximum allowable stress (SE) to be exceeded by
20 percent if the duration of the pressure (or temperature) increase
is hmited to less than 1 percent of any 24-hour period. Since' the
halon piping is normally unpressurized the system discharge period
satisfies this criteria. Therefore, the piping calculations set out in this
paragraph are based on values of SE which are 20 percent greater
than that outlined above in paragraph four (per appendix A of the
Power Piping Code). The specific values for maximum allowable
stress used in these calculauons are as follows:
A-106 Seamless, Grade C
Schedule 40--% m. thru
A-106/A-53 Seamless, Grade B Schedule 40--% an. thru
A-106/A-53 Seamless, Grade A Schedule 40--% m. thru
A-53 E R W Grade B
Schedule 40--% an thru
A-53 E R W G r a d e ' A
Schedule 40--% m. thru
A-53 Furnace Weld Class F
Schedule 40--% an thru
Schedule 8 0 - - 8 in NPS
ASTM
ASTM
ASTM
ASTM
ASTM
A-106 Seamless, Grade C
Schedule 40--% in
A-106/A-53 Seamless, Grade B Schedule 40--% an
A-106/A-53 Seamless, Grade A Schedule 40--% m.
A-53 E R W Grade B
Schedule 40--% in.
A-53 E R W Grade A
Schedule 40--% in
Schedule 8 0 - - 6 1 n
A S T M A-53 Furnace Weld Class F
Schedule 40--% m
Schedule 8 0 - - 4 an
Copper T u b i n g - - C o m p r e s s i o n
A-106
A-53
A-106
A-53
A-106
A-53
A-53
21000
18000
18000
14400
14400
15360
12240
ASTM
ASTM
ASTM
ASTM
ASTM
ASTM
psi
psi
psi
psi
psi
psi
psi
A-53
8160 psi
B-88
6120 psi
B-88
10800 psi
8
8
8
8
8
6
m
in
m.
m
in.
m
NPS
NPS
NPS
NPS
NPS
NPS
8
8
8
8
5
8
3
8
m.
in
in.
m.
in.
m
in
m.
NPS
NPS
NPS
NPS
NPS
NPS
NPS
NPS
Steel P i p e - - C u t Groove Connectmns
SE Value
ASTM
Grade C Seamless Pipe
ASTM
Grade B Seamless Pipe
ASTM
Grade B Seamless Pipe
ASTM
Grade A Seamless Pipe
ASTM
Grade A Seamless Pipe
ASTM
Grade B Seamless Pipe
Grade A ERW Pipe
' ASTM
Class F Furnace Welded
ASTM
Pipe
Seamless Copper Tubing
ASTM
(Annealed)
Seamless Copper Tubing
ASTM
(Drawn)
8 m. NPS
8 in. NPS
8 m NPS
8 m NPS
8 in NPS
1 ½ m. NPS
8 an NPS
B-88
B-88
B-88
B-88
B-88
B-88
Seamless,
Seamless,
Seamless,
Seamless,
Seamless,
Seamless,
thru
thru
thru
thru
thru
thru
thru
thru
Fittings
Drawn
Drawn
Drawn
Annealed
Annealed
Annealed
Type
Type
Type
Type
Type
Type
\
K
L
M
K
L
M
¼ m. thru 8 in
¼ an thru 3 m.
¼ m thru 1 ½ m
¼ m thru 1 m.
¼ in thru ¾ in
¼ an O N L Y
Minimum Pipins Requlremems
Halon 1301 S ~ e m s - - 600 psi Charging Pressure
Steel Pape--Threaded Connections
A S T M A-106 Seamless. Grade C
Schedule 40--% m thru 8 m. NPS
A S T M A-106/A-53 Seamless, Grade B Schedule 4 0 - - ~ in "thau 5 m. NPS
Schedule 8 0 - - 6 an thru 8 an NPS
A S T M A-106/A-53 Seamless, Grade A Schedule 40--% m. thru 2½ an. NPS
Schedule 8 0 - - 3 m. thru 8 m NPS
A S T M A-53 E R W Grade B
Schedule 40--% in thru 3 m. NPS
Schedule 8 0 - - 4 a n thru 8 in. NPS
A S T M A-53 E R W Grade A
Schedule 40--% an thru 1¼ m. NPS
Schedule 8 0 - - 1 ½ in thru 8 i n NPS
A S T M A-53 Furnace Weld Class F
Schedule 40--% in. thru ½ m NPS
Schedule 8 0 - - N in thru 2½ in. NPS
Schedule 120--3 m thru 8 in. NPS
Steel Pipe--Welded Connections
NOTE 1: When using rolled ~oove connections, or welded
connections with intemal'prgjections (backup rings, etc.), the
hydraulic calculations should consider these factors.
A-106 Seamless, Grade C
Schedule 40--% in
A-106/A-53 Seamless, Grade B Schedule 40--% m
A-106/A-53 Seamless, Grade A Schedule 40--1/~ in
A-53 E R W Grade B
Schedule 40--% an.
A-53 E R W Grade A
Schedule 40--% m.
Schedule 8 0 - - 8 in
A S T M A-53 Furnace Weld Class F
Schedule 40--% m
Schedule 8 0 - - 4 in.
Schedule 120--8 m
ASTM
ASTM
ASTM
ASTM
ASTM
NOTE 2: Pipe supplied as dual stenciled A-120/A-53 Class F meets
the requirements of Class F furnace welded pipe ASTM A-53 as listed
above. Ordinary cast-iron pipe, steel pipe coni'orming to ASTM A120, or nonmetallic pipe should not be used.
I~OTE 3: All grooved couplings/fittings should be listed/approved
for use with Halon 1301 extinguishing systems.
Copper T u b i n g - - C o m p r e s s i o n
ASTM
ASTM
ASTM
ASTM
ASTM
ASTM
NOTE 4: The above calculations do not apply to extended discharge
exceeding 14.4 minutes.
NOTE 5: Compression fittings should be listed approved for use with
the type of tubing and pressures per 2-2.3 of this standard (600 psi
systems 1000 psi working pressure; 360 psi systems 620 psi working
pressure).
600
B-88
B-88
B-88
B-88
B-88
B-88
Seamless
Seamless
Seamless
Seamless
Seamless
Seamless
thru
thru
thru
thru
thru
NPS
thru
thru
NPS
8
8
8
8
6
Type
Type
Type
Type
Type
Type
NPS
NPS
NPS
NPS
NPS
3 in NPS
6 m. NPS
Fittings
Drawn
Drawn
Drawn
Annealed
Annealed
Annealed
in
m
m
m.
in
K ¼ in. thru 1 ¼ in
L ¼ m. thru ¾ in
M ¼ in thru 3~ in.
K ¼ in thru 3& in.
L DO N O T U S E
M DO N O T USE"
NFPA 12A -- A92 TCR
A-2-2.1.5 Pressure operated ~t!inder valves are opened by the
application of ~ilotPressure from the halon cylinder or from a
separate pressure source. Depending on the particular valve design,
the pilot pressure must either be applied to a special actuation port
or to the discharge outlet of the cylinder valve. A leak in source of
pilot pressure can build up sufficient pressure in dosed sections of
pilot actuationpipe to cause the cylinder valve to open. To prevent
such accidental-dlscharge, a pressure vent must be installed m any
closed section of pipe which xs used to supplypressure. The vent
,
must be sized or otherwise designed so that when actuation is
required sufficient pilot pressure can be built up in the pilot pipe or
discharge manifold to reliably open all cylinder valves. '
250
®
20¢
_z
A-2-2.$
\
150
(a) 300 lb class malleable iron fittings, sizes through 3 in., are
acceptable. Forged steel fittings should be used for all larger sizes.
Flangedjoints should be class 600 lb.
,
(b) 300 lb class malleable iron fitdngs are acceptable through 3 in.
IPS and 1,000 ductile iron or forged steel fittings should be used in
larger sizes. Flangedjoints should be 300 lb class.
.
~~-
IOC
The ab6ve listed materials do not preclude the use of other
materials which would satisfy the requirements of 2-2.3.
(c) Pressure-temperature ratings have been established for certain
types of fitdnl~s. A list of ANSI standards covering the different types
of fittings is gaven in Table 126.1 of ANSI B31.1 Where fittings not
covered by one of these standards are used, the design recommenda.
tions of the manufacturer of the fittings shall not be exceeded.
5~
20
40
60
80
I00
EQUIVALENT LENGTH IN FEET
A-2-2.5.3 The type and size of the nozzle can be identified by part
number, orifice code, orifice diameter, or other sditable markings.
The marking shaU be readily discernible after installation.
For SI Units: I ft = 0.3048 m; 1 psi = 0.068 95 bar.
Figure A-&2(a) Comparison of test data with
calcuIated pressure drop using two-phase
flow equation,
A-2-8.2.1 Detectors installed at the maximum spacing as lisied or
approved for fire alarm use may resuh in excessive delay in agent
rel-ease, especially where more than one detecu.'on device is required
to be in alarm before automatic actuation results.
'
"
•Fricdon losses occur as the fiquid Halon 1301 flows through the
pipeline to the discharge orifice. Allowance must be made for the
equivalent lengths of the container valve, dip tube, and flexible
connectors, selector valves, .time delays, and other installed equipment through which the agent must flow. Equivalent lengths for
these components must be obtained from the approval laboratory
listings for the individual components. Equivalent lengths of common
pipe fittings and values are given in Tables A-3-2(a) and A-S-2(b).
A-2-S.&7 Manual controls should be located at the exit from the
enclosure, preferably on the door latch side.
A-2-8.5".$ The abort switch should be located near the means of
egress for the area.
"A-2-$.6 Accidental discharge has been recognized as a significant
factor in unwanted Halon 1301 emissions.
Changes in elevation are accounted for by the foUo~ng equation:
Equipment lockout or service disconnects can be instrumental in
preventing false discharges when the Halon 1301 system is being
tested or serviced. In addition, servicing of air conditioning systems
with the release of refrigerant aerosols, soldering, or turning electric
plenum heaters on for the first time after a long period of idleness
.
may trip the Halon 1301 system. When used, an equipment service
disconnect switch should be of the keyed-access tltpe if external of the
controlpanel or m a y b e of the toggle type if within the locked control
panel. Either type should annunciate at the panel when in the out of
service mode. Written procedures should be established for taking
the Halon 1301 system out of service.
'
Ap-
P × AEL
144
Where
A P = Pr(ssure drop, psi.
p
= Pipeline density of agent at point of elevation
chatl~e. II) (u ft.
Net ( h a n g e in eh,~atiou within the piping section"
AEL =
increa',c ( ÷ ) at~d decr¢'ase ( - )
Table A-$-2(a) Equivalent Length in Feet of Threaded
Pipe Fittings Schedule 40 Steel Pipe
A-3-2 System Flow Calculations. The flow of nitrogen-pressur~ed
Halon 1301 has been demonstrated to be a two-phase phenomenon;
that is, the fluid in the pipin[g consists of a mixture of hquid and
vapor. In past editions ofth~s standard, an effort was made to detail a
portion o f a complex calculation method which is used to determine
Palipeline pressures, densities and other design factors. Unfortunately,
I the factors necessary for this very complex calculation were not
listed. For example, the formulas that address heat transfer between
the agent and the piping network were not included nor were the
adjustments for the fldw of agent through a tee. Many of the
necessary final adjustments to the calculations are proprietary.
Without this data, and much more, no flow calculation for unbab
anced systems can be precise enough.
Pipe
Size,
in.
,
Elbow
Std. 45 °
Elbow
Std. 90°
%
0.6
0.8
1.0
1.3
1.7
2.0
2.6
3.1
3.8
5.0
6.3
7.6
1.3
1.7
2.2
2,8
3.7
4.3
5.5
6.6
8.2
10.7
13.4
16 2
½
¾
1
The tables, graphs and calculations used in this section are provided
to demonstrate the basis on which many calculation methods are
founded. This infoi'mation'is not adequate and must not be
considered as complete enough for design purposes. Only those
calculation methods that are listed should be used for design ,
PUrposes.
1¼
1½
2
2½
3
4
5
6
.601
Elbow 90 °
Long Rad.
& Tee
T h r u Flow
0.8
1.0
1.4
1.8
2.3
2.7
3.5 ,
4.1
5.1
6.7
8.4
10.1
Tee
Side
Union
Coupling
or
Gate Valve
2:7
3;4
4.'5
5.7
7.5
8.7
11.2
1"3.4
16.6
21.8
27.4
32.8
0:3
0.4
0.5
0.6
0.8
0.9
1.2
1.4
1.8
2.4
3.0
3.5
NFPA 12A - - A 9 2 TCR
Table A-S-2(b) Equivalent Length in Feet of
Welded Pipe Fittings Schedule 40 Steel Pipe
70
PSIG
STORAGE
600
Pipe
Size,
in.
Elbow"
Elbow
Std. 45 °
Std. 9 0 °
0.2
0.3
0.4
0.7
0.8
1.1
3/s
V2
3A
,
1
0.5
1.4
1¼
IV2
2
2½
3
4
5
6
0.7
0.8
1.0
1.2
1.5
2.0
2.5
3.0
1.8
2.1
28
3.3
4.1
5.4
6.7
8.1
Elbow 90 °
Long Rad.
& Tee
Thru Flow
0.5
0.7
0.9
1.1
1.5
1.7
2.2
2.7
3.3
4.4
5.5
6.6
Tee
Side
,
1.6
2.1
2.8
3.5
4.6
5.4
6.9
8.2
IO.2
13.4
16.8
20.2
Valve
60
0.3
0.4
0.5
0.6
0.8
0.9
1.2
1.4
1.8
2.4
3.0
3.5
40~
so
r A
_z
o
360 PSIG
w
e,lY/
°//;¢
I
~-
Design flow rates should be high enough to ensure complete mixing
of the liquid and vapor phases in the pipe line.
////
3o
For proper system flow calculation and performance, it is necessary
that a homogenous mixture of the liquid and vapor phases be present
during equilibrium pipeline flow. - .
.f
- 20
In other words, highly turbulent flow is required in the pipeline to
prevent separation of the liquid and vapor phases. Turbulent flow is
generally attained whenpipeline flow rates exceed the minimum flow
rates given in Table A-3-L3.1 (a).
A-$1.5.1 The discharge nozzle is the device that ultimately delivers
the agent to the hazard area. Its function is two-fold: (1) tt distributes the agent in an optimum manner in the hazard, and (2) it
controls the system discharge rates." The maximum nozzle flow rate is
controlled by the flow that the feed pipe can deliver. The maximum
pipeline flow rate can be theoretically calculated by means of the twophase equation. Fih,'ure A-3-1.3.1 (a) shows the calculated maximum
open-end pipe specific flow rate versus total terminal pressure. The
general shape of the curve is also characteristic of nozzle flow curves.
lo
/
f
A
I00
THEORETICAL MAXIMUM PIPELINE
FLOW DENSITIES V$ TERMINAL PRESSURES- -
300
200
"
400
500
TERM,NALeRESSURES-PS'G
Figure A-3-1.3.1 (a)
Table A-3-I.3.I (a) Minimum Design Flow Rates to Achieve
Turbulent Pipeline Flow
Since the flow rate discharged from a nozzle or pipe depends on the
energy available, the terminal pressure must be considered to consist
of two parts: (1) the static pressure (the c~uantity calculated by the
pipeline pressure drop) and (2) the velocity head energy.
Nominal Pipe
Diameter
In.
Both quantities can contribute to the energy available to discharge
th.e agent from the nozzle. The velocity heffd in psi can be calculated
from the following equation:
Where:
J
Gate
Schedule 40
Minimum Flow Rate
Lb/Sec
1/4
s/s
0.20
0.34
0.68
1.0
v e l o c i t y h e a d = _3 .63 × _ ~
pD 4
3/,
2.0,
1
Q is t h e nozzle flow r a t e i n l b s / s e c
1¼
1~
2
2~
3
4
3.4
5.8
8.4
13
19.5
33
58
p is t h e di~nsity in l b s / c u ft a t t h e
Terminal static pressure
5
6
D is t h e feed p i p e d i a m e t e r in in.
For SI Units"
NOTE: The calculation method described in this standard is
based on 70°F (21°C). For unbalanced systems, ffthe agent
storage temperature is expected to vary by more than 10°F
(5.5°C) from this temperature, the actual agent quantity
discharged from each nozzle may vary siguificandy from the
calculated agent distribution.
95
127
Schedule 80
Minimum Flow Rate
Lb/Sec
0.11
0.24
0.48
0.79
1.9
2.8
4.8
7.5
13
17
26
48
81
109
1 lb/sec = 0 454 kg/s ~
The percent of agent in piping is defined by the following equation
and should not exceed 80 percent of the charged weight.
602
NFPA 12A - - A92 TCR
24oo
Percent in Piping = 100 Y (Vp) (i5 )
W
I ' END OF LIQUID
~,oo
Where:
y
S u m m a t i o n o f ( V p ) (~) v a l u e s for all
pipeline sections.
. ,
=
I n t e r r i a l v o l u m e o f e a c h s e c t i o n o f piping' ( c u f t )
= - . A v e r a g e p i p e l i n e d e n s i t y o f a g e n t for
e a c h s e c t i o n o f p i p i n g ( l b s / c u ft)
=
l n i t i a l c h a r g e w e i g h t o f H a l o n !301
..3
=
Vp
W
' \
o
~ 200
INITIAl. FILL D E N S l T y J
IN LBS.IOJ. FT.."T-- '
a,
o
I-
O)
z
I00
W
'
CALCULATED PRESSURE
R E C E S S ON
FOR ~OPSIGSTORAGE
(lbs).
NOTE: Internal,volume figures for steel pipe and tubing are
given in Tables A-3-2.3(a) and A-3-2.3(b). ,
•¢
I
..
0
n.
Flow calculations should be based on average pressure conditions
existing in the system when half of the agent has been discharged.
from the nozzles. The average pressure in the storage container is
determined on the basis of the pressure recession in the storage
container and the effect of percent of agent in the piping during
discharge. The calculated pressure recession for b o t h 600 and 360"
l~ig storage is plotsed on F'gui-es A-3-1.3.1Co) and A-3-1.3.1(c), respectively.
I00
40
60
80 '
PERCENT OUTAGE
of Charged Weight Having Left Container)
2O
0
-(Percent
Figure A-3-1.3.1 (c) Calculated pressure recession for 360 psig storage.
600
PERCENT IN PIPELINE
The rate of pressure recession in the storage contalnhr depends on
"the initial filling density as illustrated in Figures A-3-1.3.1 (b) and A-31.3.1 (c)). If the pipeline has negligible volume compared to the
quantity of agent to be. discharrged, the average., container p.ressure for
pressure drop calculauons would be the point m the recesmon curve
where 50 percent of the charge has been expelled from the conminer. In many systems this will not be the case because a substantial
portion of the charge will reside in the piping during discharge,
reducing the average container pressure durang actual discharge
from the nozzle.
-
(3
500
" ~
60~ PSI6 SYSTEM
400
Figure A-3-1.3.1 (d) illustrates the condition where 20 percent of the
agent supply byweight resides in the piping during discharge. The
average storage pressure for flow calculation for the 600 psig s~tem
with initial filling density of 70 l b / c u ft is reduced from a maximum
of 403 p silg to 355 psig Proceedin... g.in t h i s w aa,v the
ey
rage container
pressure for flow calculauon as a logacal funcuowof the percent of
agent in thepiping as given in Figure A-3-1.3.1(e). Several factors
combine to allow a simple extrapolation of the average storage
container pressure versus percent of agent in the piping curves up to
a calculated 80 percent of the supply in the pipelihe-.
uJ
,
~"
re
=
,'
600
500
"~'~
~
END OF LIQUID
I
LINE
0
0
20 "
40
60
80
100
PERCENT OUTAGE
(Percent of Charged Weight Having Left Container)
Figure A-3-1.3.1(d) Percent Outage.
z
u
u.I
- 70
300
INITIAL FILL DENSITY
IN LBS./CU. FT.
~
1
"~
• The quantity of agent in the piping system during discharge is a
function of the actual volume of the piping times the average density
• of the agent. The average density cannot be accurately determined
until after the terminal pressurehas been calculated. The problem ,
does not have a direct solution; however, the following equation may
be used to estimate the percent in piping for calculating purposes.
•This is based on the probability that the terminal pressure will be
near the minimum permitted.
x
I
Ill
o 200
u~
CALCULATED
Z
PRESSURE
KI
RECESSION
FOR
600 PSIG STORAGE
-
t~J
re
::a I 0 0
tn
% in Piping - ( W / V . ) + Ks
\
Where:
.W
- O
0
20
40
60
PERCENT OUTAGE
80
I00
W
=
Initial charge weight of Halon 1301, lb
Vp
=
Internal pipe volume, cu ft
Ka and I~ = Constants from Table A-1-10.6.4
(Percent of Choroed Weight Hovino Left Container)
Figure A-3-1.E1 (b) Calculated pressure recession for 600 psig storage.
t
603
NFPA 1 2 A - A92 TCR
AVERAGE STORAGE CYLINDER PRESSURE V$
Ioo
PERCENT OF THE AGENT SUPPLY NEEDED TO FILL THE PIPELINE
9o
eo
450 ~
~
400
~"
~
,fAC
7o
.~
.a
~ 5o
u~ 350
~
300
,o
f
iO
250
0
IO0
ISO
200
250
300
350
PIPELINE PRESSURE IN PSlG
400
450
5OO
Figure A-3-1.3.1 (f) Pipeline density for 600 psig systems
based on constant enthalpy expansmn.
15o
0
10
20
30
40
50
60
70
80
PERCENT OF AGENT TO FILL PIPELINE
F i g u r e A-S-1.3.1 (e) P e r c e n t o f agent to f i l l
90
pipeline.
8C
An alternative solution of the percent in piping after terminal
pressures have been calculated is to use the percentage inpiping
equation.
. '. Average density values can be obtained from
Figure A-3-1.3.1 (f) for the 600 psig systems and from Figure A-31.3.1 (g) for the 360 psig systems.
:Z/4 /
7C
For piping systems, pressure drop should be calculated by means of
the two-phase equation given below or by any other method approved
by the authorityhavingfurisdiction.
--
S
z
j
z
1.013D s zsy
Q2 = L + 8.08D' zsZ
~
2C
Where:
IO
DQ
=
Flow rate, lbs/second
= Inside pipe diameter, in.
L
= Equivalent length of pipe, ft
Y& Z = Factors depending on density and pressure
0
I00
In no case should the nozzle pressure be lower than the listed
pressure.
120
140
160
ISO 200 220 L:qO 260
'PIPELINE PRESSURE IN PSIG
280
300
320
Figure A-3-1.3.1 (g) Pipeline density for 360 l~sig systems
based on constant enthalpy expansmn.
NOTE: This flow equation contains a friction factor based on"
commercial steel pipe.
T a b l e ,4,-$-1.$.1Co)
Constants to D e t e r m ; n e P e r c e n t o f
604
Agent in Piping
Storage Psig
600
600
600
600
Filling Density
70
60
50
40
7180
7250
7320
7390
gt
46
4O
34
28
360
360
360
360
70
60
50
40
6730
6770
6810
6850
52
46
40
34
K,
NFPA 12A -- A92 TCR
Table A-3-1.3.1 (c)
Internal Volume of Steel Pipe
Cubic Feet per Foot of Length
P
F
y =
--
P,
Nominal Pipe
Diameter
in.
Schedule 40
Inside Diameter
in.
huh
in.
h~/h
• ¼
0.364
0.493
0.622
0.824
1,049
1.380
1.610
2.067
2.469
3 068
3.548
4.026
0.0007
0.0013
0.0021
0.0037
0.0060
0.0104
0.0141
0.0233
0.0332
0.0513
0 0687
0.0884
0.302
0.423
0.546
0,742
0.957
1,278
1.500
1,939
2.323
2.900
3.364
3.826
0.0005
0.0010
0.0016
0.0030
0.0050
0.0089
0.0123
0.0205
0.0294
0.0459
0.0617'
0.0798
½
¾
1
1¼
1½
2
2½
3
3½
4
Size
pdP
/
J
' S c h e d u l e 80
Inside
Diameter
p'
-Z = In P
Where:
In
=
Storage pressure, psia
Pipeline pressure, psia
Density at pressure Pv l b s / c u ft
Density at pressure P, l b s / c u ft
Natural logarithm
Table A-$1.3.1 (d)
Internal Volume of Copper Tubing
Actual Inside
l n t e r n ~ Volume
Type
-Diameter-inches
h31h
¼
M
--L
0.315
0.0005
K
0.305
0.0005
M
0.450
0.0011
L
0.430
0.0010
K
0.402
0.0009
½
M
0.569
0.0018
L
0.545
0.0016
K
0.527
0.0015
M
0.811
0.0037
L
0.785
0.0034'
K
0.745
0.0030
I
M
1.055
0.0061
L
1.025
0.0057
K
0.995
0.0054
1¼
,M
1.291
0.0091
L
1.265
0.0087
K
1,245
0.0085
1½
M
1.527
0.0127
L
1.505
0.0124
K
1.481
0.0120
2
M
2.009
0.0220
L
1.985
0.0215
K
1,959
0.0209
2½
M
2.495
0.0340
L
2 465
0.0331
K
2.435
0.0323
3
M
2.981
0.0485
L
2.945
0.0473
K
2.907
0.0461
3½
M
3,459
' 0.0653
L
3.425
0.0640
K
, 3.385
0.0625
4
M
3.935
0.0845
L
3 905
0.0832
K
3 857
0.0811
Sample Calculation. An 80-1b supply of a g e n t is to be discharged in
10 seconds t h r o u g h the piping system shown in Figure A-3-1.3.1 (h).
T h e a g e n t storage c o n t m n e r is pressurized to 360 psig a n d has a
filling density o f 7 0 ' l b / c u ft.
Figure A-3-1.3.1(h) Calculated Solution.
A direct solution o f the flow equation for pressure is n o t possible;
however, the equation can be r e a r r a n g e d to solve for Y, which is
related to pressure.
Y~=
Y, + ( L Q 2 / A ) + B ( Z 2 - Z , ) Q 2
Where:
Z~
B
L
Q
D
=
=
=
=
=
=
=
=
=
Yfactor at start o f section
Yfactor at e n d o f section
Z factor at start o f section
Z factor at e n d o f section
1.013D 5.25
1 7.97/D 4
Equivalent length o f section, ft
Flow rate, lbs/sec
I.D. o f pipe, in.
NOTE: A a n d B factors are for steel pipe.
T h e Y a n d Z factors d e p e n d o n b o t h s t o r a g e p r e s s u r e a n d filling
density; therefore, separate tables are r e q u i r e d for each storage
condition. Tables A-5-1.3.1 (f), (g), (h), a n d (i) are for t h e 600 psig
systems with filling densities o f 70, 60, 50, a n d 40 l b / c u ft. Tables A-31.3.1 (j), (k), (1), a n d (m) are for the 360 psig systems with the same
filling densities.
T w o - P h a s e Solution
Start End
Section
1-2
2-3
2-4
Pipe
1 " Sch. 40
3A" Sch. 40
~A" Sch 40'
L
27'
15'
15'
EQL
58'
19'
19'
Elevation
7'
0'
0'
Rate
8
4
4
(I) Calculate A a n d B.
For 14nch pipe, A = 1.302 a n d B = 6.59.
For 3/4-inch pipe, A=10.3666 a n d B = 17.3.
T h e two-phase flow equation
. b e c o m e s specific for
H a l o n 1301 w h e n t h e Y a n d Z factors are based o n the p r o p e r
pressure a n d density values u s i n g the following equations:
(2) D e t e r m i n e Piping Volume. U s i n g Table A-3-1.3.1 (c).
(3) Estimate Percent in Piping.
6730
= 19.5%
% in P i p i n g = ( 8 0 / 0 , 2 7 3 ) + 52
605
Psig
243
197
197
Psig
197
181
181
NFPA 12A m A92 TCR
The solution would then be reiterated until reasonable agreement
between the estimated percent in the pipe and the final calculated
quantity is obtained. Such reiteration is, however, time consuming
and subject to numerical error when manual calculation means are
used. For this reason the two-phase method is normally used with a
programmed computer,
(4) Determine Average Container Pressure During Discharge.
Using Figure A-3-1.3.1 (e), based on the estimated 19.5 percent in
piping the average storage container pressure in 243 ps~g.
(5) Elevation Correction. Before calculating pressure drop due to
friction, thepressure change due to elevation in Section 1-2 must be
calculated. The relationship in A-3-2 is used:
In unbalanced systems it is important to use the proper orifice size
at each nozzle to give the desired flow rate at the calculated terminal
pressure. This is based on the flow characteristics of individual
hozzles .as provided in the manufacturer's design manual.
p x AEL
144
AP=
A-5-3 Flammable liquid and gas fires are subject to prompt extin~mishment when Halon 1301 is quickly introduced into the enclosure
m sufficient quantity to provide an extinguishing concentration for
the particular materials revolved. NFPA 69, Standard on E~lo~'ion
Pwoent/on Systems, shall be referred to when possible flammable
concentrauons of gases make explosion protection techniques
necessary.
The elevation change (EL) is 7 ft. The density (P) of the Halon
1301 at the 243 psig starting pressure of the section is found to be 83
lb/cu ft in Figure A-3-1.3.1 (g) on the 70 l b / c u ft fill density curve.
The pressure loss due to the 7 ft increase in elevation is:
83×7
144
P
= 4 psi
A-$-3.$ The design of total flooding Halon 1301 systems only beneath
the raised floor of EDP facilities when the occupied space above the
raised floor is not similarly protected by a total flooding Halon 1301
system does not meet the intent of this standard. Such a desi~, does
not comply with the definition of a total flooding system or with this
chapter.
New start psig = 243 - 4 = 239
(6) Determine Y1 and Zlfrom Table A-3-1.3.1 (j).
For a starting pressure of 239 psig:
LeA~ge o f H a l o n 1301 Through Enclosure Openings. Halon 1301
discharged into an enclosure for total flooding will result in an air/
agent mixture that has a higher specific gravity than the air surrounding the enclosure. Therefore, an), opening in the walls of the
enclosure will allow the heavier mr/agent mixture to flow out of the
enclosure, being replaced with lighter outside air flowing into the
enclosure through the same opening. The rate at which agent is lost
through openings will depend on the height and width of the
opening, the location of the opening in the wall, and the concentration of agent in the enclosure.
= 2819
~x
= 0.173
(7) Determine ¥s from Equation.
¥s ffi 2819 + 58(8) I/1.302 + 6.59 (Z~ -0.173) (8) ~
The Z term is small and may be neglected for initial solution.
Ys ~ 5670
Fresh air entering the enclosure will collect toward the top, forming
an interface between the air/agent mixture and fresh air. As leakage
oceeds, the interface will move toward the bottom of the opening.
e space below the interface will contain essentially the original
extinguishing concentration of agent, whereas the upper space will
be completeIy unprotected. The rate at which the interface moves
downward increases as concentrations of agent increase, so that
simply injecting an overdose of agent initiaUy will not provide an
extended period of protection.
(8) Determine Terminal pressure.
The terminal pressure of Section 1-2 is 200 psig from Table A-31.3.1(j). At this point the Z factor is about 0.475. Using this value for
Z~, the last term of the equation becomes 127.
Then Ys = 5670 + 127 = 5797
The final terminal pressure of Section 1-2 is then between 198 and
197 psig. Use 197 psig.
A-&4.1 Where an explosion potential exists due to the presence of
gaseous, volatile, or atomized fuels either before or following a fire,
NTPA 68, Guidefor Venting of Deflagrations, and NTPA 69, Standard on
Exp/os/on Prevent/on Systems, covering vapor detection and explosion
venting and suppression shall be consuited. In particular, extreme
caution shall be taken following inerting of a rich fuel-air mixture
since compartment leakage or ventilation will cause the mixture to
pass through the explosive range of concentrations when fresh air is
admitted.
(9) Section 2-3.
For the next section:
~.,
= 5797 + 19(4)2/0.366 + 17.3 (Z~ -0.475) (4) !
= 6628
Terminal pressure = 182 psig
A-3-4.1.2 (a) Applicability ofFlameExtinguishraent Concentrations. The
minimum design concentration required to extinguish normal fires
involvin~ certain flammable gases and liquids at atmospheric pressure
are apphcable ff the conditions for reflash or explosion do not exist.
~ffi 0.652
= 6628 + 17.3 ( . 6 5 2 - . 4 5 2 ) ( 4 ) 2
6628 + 46 ffi 6674
(b) Temperature Sensitivity. The flame extinguishing concentration
required for some fuels depends on the fuel temperature. All fuels
sh~l be tested at at least two temperatures to determine temperature
sensitivity.
Terminal pressure is between 182 and 181 psig. Use 181 psig.
T a b l e A-3-1.$.1 (e) Precalculated A and B Factors f o r
Steel Pipe
Pipe Size
Nominal
sA
1
1¼
t~,i
2
21A
3
4
5
6
Schedule 40
A
0.02472
0.08375
0.3666
1.302
5.495
12.34
45.83
115.3
364.4
1518
4972
13050
Schedule 80
B
A
135
53.3
17.3
0 01106
0.04225 .
0.2115
6.59
. 2.20
1.19
0.8043
3.672
8.513
0.437
0.216
0.090
0.0304
0.0123
0.00589
32.76
84.6
271.1
1162
3875
9959
B
249
89.7
26.3
9.51
2.99
1.58
0.564
0.274
0.113
0.0372
0.0149
0.00724
606
NFPA 12A - - A 9 2 TCR
Table A-3-1.3.1 (f) Halon 1301 at 600 pstg and
70 lbs/cu ft Y and Z Factom
PSIG
Z
400
390
.006
'.028
380
370
0
I
2
3
4
5
6
7
8
9
290
1243
194
1149
97
1054
0
960
0
865
0
769
0
674
0
o
o
578
482
386
.051
".076
2176
3086_
2084
2996
1991
2906
1898
2816
1806
2725
1712
2634
1619
2543
1525
2451
1432
2360
1338
2268
360
350
.102
.129
3974"
4838
3886
4753
3798
4667
3710
4581
3622
4495
3533
4~09
3444
4323
3355
4236
3266
4149
3176
4062
340
330
.159
.191
5678
6492
5595
6412
5512
6331
5428
6251
5345
6169
5261
6088
5177
6007
5093
5925
5068
5843
4923
5760
320
310
.224
.260
7281
8042
7203
7967
7125
7892
7047
7816
6968'
7741
6890
7665
6811
7588
6731
7512
6652
7435
6572
7358
300
290
.298
.339
8776
9482
8704
9412
8631
o 9343
- 8559
9273
8486
9203
8413.
9132
8339
9062
82/~5
8991
8191
8919
8117
8848
280
270
.382
.429
10158
10805
10092
]0741
10025
10678'
9958
10614
9891
10550
9823
10485
9756
10420
9688
10355
9619
10290
9551
10224
260
250
.478
.531
11421
12007
11361
11950
11300
11892
11239
11834
11178
11776
11117
11718
11055
11659
10993
11600
10930
11541
10868
11481
240
230
'.588
.649
12561
13084
12507
13033
12453
12982
12398
12930
12343
12878
12288
12826
12232
12774
12176
12721
12120
12068
12064
12615
220
210
.713
.782
13575
14034
13527
13990
13479
13945
13431
13900,
13382
13854
13331
13808
13284
13762
13234
13716
13184
13669
13134
13622
200
190.
.855"
.934
14462
14859
14421
14820
14379
14782
14337
14743
14295
14704
14252
14664
14209
14624
14166
14584
14122
14544
14078
14503
180
170
1.017
1.105
15225
15561
15190
15528
15154
15496
15118
15463
15082
15430
15046
15396
15009
15363
14972
15329
14934
15294
14897
15260
160
150
1.198
1.297
15868
16146
15838
161'20
15809
16093 ~
15779
16066
15748
16038
15718
16010
15687
15982
15656
15954
15624
15926
15593
15897
140 - 1.402
130
1.513
16398
16624
16374
16603
16350
16581
16325
16559
16301
16537
16276
16514
16250
16491
'16225
16469
16199
16445
16173
16422
120
110
1.631
1.755
16826
17004
16807
16987
i6787
16970
16768
16953
16748
16935
16728
16918
16708
16900
16687
16882
16666
16863
16645
16845
100
90
1.888
2.029
'17161
17298
17147
17286
17132
17273
17116
17259
17101
17246
17085
17232
17070
17219
17054
17205
17037
17190
17021
17176
80
70
2.181
2.347
174i7
17518
17406
17509
17395
17499
17383
17489
17372
17479
17360
17469
17348
17459
17336
17449
17324
17438
17311
17428
60
2.530
17603
17595
17587
17579
17571
17562
17554
17545
17536
17527
6O7
NFPA 12A - - A 9 2 TCR
Table A-$-l,3.1(g) Halon 1301 at 600 psig and
60 lbs/cu ft Y and Z Factors
0
1
2
3
4
5
6
7
PSIG
Z
420
410
.019
.039
956
1893
861
1800
766
1707
671
1614
575
1520
480
1426
384
1333
289
1239
400
390
.060
.083
2811
3709
2720
3620
2629
3531
2537
3442
2446
3352
, 2354
3262
2262
3172
380
370
.[06
.132
4587
5443
4500
5358
4413
5273
4325
5188
4238
5103
4150
5017
360
350
.158
.187
6277
7089
6195
7009
6112
6929
6029
6848
5946
6767
340
330
.217
.249
7877
8642'
7800
8566
7722
8491
7643
8415
320
310
.283
.319
9381
10095
9308
10025
9235
9954
300
290
.358
.399
10783
11444
10715
11379
280
270
A42
.489
12077
12683
260
250
.538
.591
240
230
8
'
9
193
1144
96
1050
2170
3082
2078"
2992
1985
2901
4062
4932
3974
4846
3886
4760
3798
4673
5863
6686
5779
6605
5696
6523
5612
6442
5527
6360
7565
8339
7486
8263
7407
8186
7328
8109
7249
8032
7169
7955
9162
9883
9088
9812
9014
9741
8940
9670
8866
9598
8791
9526
8717
9454
10647
11314
10579
i1248
10511
11183
10442
11117
10373
11050
10304
10984
10235
10917
!,0165
10850
12015
12624
11953
12564
11890
12564
11827
12444
11764
12384
11701
12323
11637
12262
11573
12201
11508
12139
13261
13809
13204
13756
13148
13702
13090
13648
13033
13593
12976
13539
12918
13484
12859
13428
12801
13373
12742
13317
.647
.707
14329
14820
14278
14772
14227
14724
14176
14675
14125
14627
14073
14578
14021
14529
13968
14479
13916
14430
13863
14379
220
210
.770
.838
15281
15713
15236
1567l
15191
15629
15145
15586
15100
15543
15054
15500
15008
15457
14961
15413
14914
15369
14867
15325
200
190
.909
.985
16116
16490
16077
16454
16037
16417
15998
16381
15958
16344
15918
16306
15877
16269
15837
16231
15796
16193
15754
16154 '
180
170
1.066
1.152
16836
17154
16802
17123
16769
17093
16735
17061
16701
17030
" 16666
16998
16632
16966
16597
16934
16561
16902
16526
16869
160
150
1.243
!.339
17445
17711
17418
17685
17389
17660
17361
17634
17332
17608
17303
17581
17274
17555
17244
17528
17214
17501
17184
17473
140
130
1.441
1.549
17951
18168
17928
18147
17905
18126
17882
18105
'17858
18084
17834
18062
17810
18041
17786
18019
17761
17996
17736
17975
120
110
1.664
1.785
18361
18534
18343
18517
18324
18501
18306
18484
18287
18467
18267
18450
18248
18433
18228
18415
18208
18398
18188
18380
18566
18714
18550
18700
\
100
90
1.914
2.052
18686
18818
18671
18806
18657
18793
18642
18781
18627
18767
18612
18754
18597
18741
18581
18727
80
70
2.201
2.363
18934
19032
18923
19023
18912
19014
18901
19004
18890
18995
18878
18985
18867
18975
18855
18965
18843
18955
18831
18944
60
2.543
19116
19108
19100
19092
19084
19076
19068
19059
19050
19041
608
NFPA 12A.-- A92 TCR
Table A-3-1.$.l(h) Halon 1301 at 600 psig and
50 Ibs/cu f t Y and Z Factors
PSIG
Z
0
450
440
.012
.030
667
1607
430
420
.049
.068
410
400
1
2
3
4
5
6
7
8
9
573
1513
478
1420
382
" 1327
287
1233
192
11.39
96
1045
0
"951
0
857
0
762
2529
3434
2437
3344
234~
3254
2254
3164
2162
3074
2070
2984
1978
2893
1885
2802
1792
2711
1700
2620
•.089
.ill
4321
5189
4233
5103
4145
5017
4056
4930
3968
4844
3879
4757
3791
4670
3702
4583
3613
4496
3523
4408
390
380
.134
.158
6038
6867
5954
6785
5870
6702
5785
6620
5701
6538
"5616
6455
5531
6372
5446
6289
5360
6205
5275
6122
$70
360
.184
.2"12
7675
8462
7595
8384
7515
8306
7435
8228
7354
8150
7273
8071
7192
7992
7111
7913
7030
7834
6948
7755
350
340
.241
.272
9227
9970
9151
9896
9076
9823 ~
9000
9749
8924
9675
8847
9601
8771
9527
8694
9452
8617
9377
8539
9302
330
320
.304
.339
10689
11385
10618
11316
10547
11247
10476
11118
10404
11109
10332
11040
10260
10970
10188
10900
10115
10830
10043
10760
310
300
.375
.414
12056
12702
11990
12639
11924
12575
11857
12511
11790
12447
11723
12382
11656
12318
11589
12252
11'521
12187
11453
12122 ~
290
280
.455
.499
13324
13919
13263
13861
13201
13802
13140
13743
-13078
13684
13016
13625
12954
13565
12891
13505
12829
13445
12766
13384
270
260
.546
,.595
14488
15031
14432
14978
14376
14924
14320
14871
14264
14817
14207
14763
14150
14708
14092 •
14654
14035
14599
13977
14544
250
.240
.647
.703
15546
16035
15496
15987
15445
15939
15394
15891
15343
15842
15292
15794
15240
15745 •
15188
15696
15136
15646
15083
15596
250
220
.762
•825
16496
16930
16451
16888
16406
16845
16360
"16802
16315
16759
16269
16716
16222
16673
16176
16629
16129
16585
16082
16540
210
200
.892
.962
17337
17716
"17297
17680
17257
17642
17217
17605
17177
17568
17137
17530
17096
17492
17055
17453
17013
17415
16972
17376
190
180
1.037
1.117
18069
18396
18035'
18365
18001
18333
17966
18301
17931
18269 .
17896
18236
17861
18203
17825
18170
17789
'18137
17753
18103
170
160
1.201
1.290
18698
18974
18669
18947
18639
18921
18610
18894
18580
'18866
18550
18839
18520
18811
18489
18783
18459
18755
18428
18726
150
140
1.384
1.484
19226
19455
19202
19433
19178
19411
19153
19389
19128
19366
19103
19343
19078
19320
19052
19297
19026
19274
'19000
19250
130
120
i.589
1.701
19682
19847
19642
19829
19622
19811
•19602
[9793
19582
19775
19561
19757 ,
19540
19738
19519
19719
19498
19700
19477
19681
110
100
1.820
1.947
20012
20158
"19996
20144
19981
20130
19965
20116
19948
20102
19932
20087
19915
20073
19898
20058
19881
20043
19864
20027
90
80
2.083.
2.229
20286
20397
20274
20387
20262
20376
20249
20366
20237
20355
20224
20344
20211
20333
20198
20321
20185
20310
20172
20298
70
60
2.385
2.555
20493
20574
20484 '
20567
20475
20559
20466
20551
20457
20543
20447
20535
20437
20527
20428
20519
20418
20510
20408
20502
,
609
NFPA 12A m A92 TCR
Table A-3-1.3.1(i) Halon 1301 at 600 pslg and
40 lbs/cu ft Y agd Z Factorl
6
7
8
9
0
946
0
852
0
758,
0
664
0
570
1970
2884
1878
2793
1785
2702
1692
2611
1600
2520
1507
2429
3871
4752
3782
4664
3693
4577
3604
4489
3515
4402
'3425
4314
3335
4225
5700
6544
5615
6461
5529
6377
5444
6293
5358
6209
5272
6125
5185
6040
5099
5955
7452
8257
7370
8177
7288
8097
7206
8017
7124
7937
7042
7856
6959
7776
6877
7695
6794
7614
9042
9808
8965
9732
8887
9656
8809
9580
8730
9504
8652
9428
8573
9351
8494
9274
8415
9197
10553
11277 "
10480
11206
10466
11134
10332
11062
10258
10990
10183
10918
10109
10845
10034
10773
9959
10700
12049
12727
11980
12660
11910
12593
11841
12526
11771
12458
11701
12391
11631
12323
11361
12254
11490
12186
11419
12118
.393
.430
13382
14014
13318
13952
13253
13890
13188
13827
13123
13764
13057
13701
12992
13638
12926
13574
12860
13510
12793
13446
300
290
.469
.511
"14623
15207
14563
15150
14503
15092
14443
15034
14382
14976
14321
14918
14260
14859
14199
14800
14138
14741
14076
14682
280
270
.555
.602
15767
16302
15712
16250
15657
16197
15601
16144
15546
16091
15490
16038
15434
15984
15378
15930
15321
15876
15264
15821
260
250
.651
.704
16812
17296
16762
17249
16712
17202
16662
17154
16611
17106 -
16560
17057
16509
17009
16458
16960
16406
16911
16354
16861
240
230
.759
.818
17756
18189
17711
18147
17666
18105
17621
18062
17575
18019
17529 '
17976
17483
17932
17437
17888
17390
17844
17344
17800
220
210
.880
.946
18597
18980
18558
18943
18518
18906
18478
18868
18437
18830
18397
18792
18356
18754
18314
18715
18273
18676
18231
18637
200
190
1.016
1.090
19338
19671
19303
19639
19268
19606
19233
19574
19198
19541
19162
19508
19126
19474
19090
19440
19054
19407
19017
19372
180
170
[.168
1.251
19979.
20264
19950
20237
19920
20209
19889
20181
19859
20153
19828
20125
19797
20096
19766
20067
19735
20038
19703
20009
160
150
1.339
1.431
20526
20764
20500
20742'
20475
20718
20449
20695
20424
20672
20398
20648
20371
20624
20345
20600
20318
20575
20291
20550
140
130
1.529
1.633
20982
21178
20961
21159
20940
21140
20919
21121
20897
21102
20876
21082
20854
21063
20832
21043
20810
21023
20787
21002
120
110
1.744
1.861
21354
21512
21338
21497
21321
21482
21304
21467
21286
21451
21269
21435
21251
21420
21233
21404
21215
21387
21197
21371
100
90
1.986
2.120
21651
21774
21638
21763
21625
21751
21611
21739
21598
21727
21584
21715
21570
21702
21556
"21690
21541
21677
21527
21664
80
70
2.264
2.420
21881
21973
21871
21964
21861
21955
21850
21947
21840
21938
21829
21929
21819
21919
21808
21910
21797
21900
21785
21891
60
2.591
22051
22044
22036
22029
22021
22013
22006
21998
21989
21981
0
1
2
3,
4
PSIG
Z
480
470
.008
.024
475
1414
380
1321
285
1227
190
1134
95
1040
460
450
.041
.058
2337
3245
2246
3155
2154
3065
2062
2975
440
430
.076
.096
4137
5012
4049
4926
3960
4839
420
410
.116
.137
5871
6711
5785
6628
400
390
.160
.184
7533
8336
380
370
.209
.236
9120
9883
360
350
.264
.293
10627
11348
340
330
.325
.958
320
310
610
'5
NFPA 12A -- A92 TCR
Table A-3-1.3.1(j) Halon 1301 at 360 psig
and 70 lbs/cu ft Y and Z Factors
0
1
2
$
4
5
6
7
8
9
.050
• 105
962
1874
868
1785
773
1696
678
1606
583
'1515
48~
1424
391
-1333
294
1241
196
1148
98
1055
.166
.233
2735
3543
2652
3465
2567
3386
2483
3307
2397
3227
2311
3146
2225
3065
2138
2984
2051
2901
1963
2819
.307
.387
4297
4994
4224
.4927
4150
4859 "
4076
4791
4002
4722
3927
4652
3851
4582
3775
4512
3698
4441
3621
4369
200
190
.475
.570
5635
6220
5573
6164
5511
6107
5449
6050
5385
5993
5322
5935
5257
5876
5192
5816
5127
5757
5061
5696
- 180
170
.673
.783
6750
7227
"6699
7181
6648
7135
-.6597
7089
6544
,7042
6492
6995
6439
6947
6385
6898
6330
6849
6275
6800
160
150
.899
1.021
7652
8030
7612
7994
7571
7958
7530
~922
7488
7885
7446
7847
7403
7809
7359
7771
7316
7732
7271
7692
140
• 130
1.149
1.282
8364
8656
8332
8629
8300
8601
8268
8573
8235
8544
8202
8515
8169
8486~
8135
8456
8100
8425
8066
8395
120
!.422
1.567
8912
9133
8888
9113
8864
9092
8839
9070
8814
9049
8789
9027
8763
9004
8737
8982
8710
8959
8684
8935
90
1.719
i.879
9324
9488
9306
9472
9288
9457
9270
.9441
9251
9425
9232
9409
9213
9393
9194
9376
9174
9359
9154
9342
80
70
2.047
2.225
9626
9743
9614
9732
9600
9721
9587
9710
9574
9699
9560
9687
9546
9676
9532
9664
9517
9651
9503
9639
.60
2.417
9840
9831
9822
9813
9804
9794
9784
9774
9764
9754
6
7
8.
9
0
390
0
293
'0
196
Z
PSIG
26O
250
240
230
,
220
210
"
110
16O
Table A-S-1.3.1(k) Halon 1301 at 360 pslg and
60 l b s / c u ft Y and Z Factors
PSIG"
0
98
1056
1
2
$
4
5
280
270
Z
.004
.051
0
962
0
868
0
774
0
678
0
583
0
487
260
250
.102
.158
1969
2834
1880
2750
1790
2665
1700
2579
1609
2494
1518
2407
1427
2321
1335
2233
1242
2146
1150
'2057
.219
.286
3650
4415
3571
4341
3491
4266
3410
4191
3330
4115
3248
4039
31~6
3962
3084
3885
3001
3807
2918
3729
220
210
.360
.440
5129
5789
5060
5726
4990
5662
4920
5597
4850
5532
4779
5466
4707
5399
4635
5333
4562
5265
4489
5197
200
190
.527
.621
6397
6952
6339
6899
6280
6845
6220
6791
6160
6736
6100
6681
6039
6625
5977
6569
5915
6512
5853
6455-
180
170
.722
.829
7456
7910
7408
7866
7359
'7823
7310
7778
7260
7734
7210
7689
7160
7643
7108
7597
7057
7550
7005
7503
160
150
.942
1.062
8316
8678
,8278
8644
8239
8609
8199
8574
8159
8538
8119
8503
8078 '
8466
8036
8429
7995
8392
7952
8354
140
i.187
1.318
8998
9280
8968
9254
8937
9227
8906
9199
8875
9172
8843
9144
8811
9115
8778
9087
8745
9058
8712
9028
1.455
1.598
9527
9741
9503
9721
9480
9700
9456
9680 " .
9432
9659
9408
9638
9383
9616
9358
9594
9332
9572
9308
9549
90
1.748
1.905
9926
10085
9909
10070
9891
1.0055
9873
10040
9855
10024
9837
10009
9818
9993
9799
9976
9780
-9960
9761
9943
80
70
2.071
2.248
10220
10334
10207
10323
10195
10313
10182
10302
10169
10291
10155
10279
10142
10268
10128
10256
10114
10244
10099
10232
60
2.437
10429
10420
10411
10402
10393
10384
10374
10364
10354
10344
240
230
150
120
110
100
,
-
.
611
NFPA 12A m A92 TCR
Table A-3-1.3.1(1) Halon 1301 at 360 pstg and
50 lbs/cu ft Y and Z Factors
PSIG
Z
0
1
2
3
4
5
6
7
8
9
290
280
.008
.051
195
1148
98
1055
0
961
0
867
0
772
0
677
0
581
0
485
0
389
0
292
270
260
.098
.150
2059
2926
1970
2841
1880
2756
1790
2670
1700
2584
1609
2498
1518
2411
1426
2324
1334
2236
124r
2148
250 ~
240
.206
.268
3747
4521
3667
4446
3586
4370
3505
4294
3424
4217
3342
4140
3260 "
4062
3177
3984
3094
3906
3010
3827
230
220
.335
.408
5247
5925
5177
5859
5106
5793
5035
5727
4963
5660
4890
5592
4818
5524
4744
5456
4670
5387
4596
5317
210
200
.487
.573
6552
7129
6491 '
7074
6430
7018
6369
6961
6307
6904
6244
6847
6181
6789
6118
6730
6054
6671
5989
6612
190
180
.666
.764
' 7658
8138
7607
8092
7556
8046
7504
7999
7452
7952
7400'
7904
7347
7856
7293
7807
7239
7758
7184
7708
170
160
.870
.981
8572
8961
8530
8924
8489
8887
8446
8849
8404
8810
8361
8772
8317
8733
8273
8693
8228
8653
8183
8613
150
140
1.097
1.220
9308
9617
9275
9587
9242
9558
9208
9528
9174
9498
9140
9467
9105
9436
9069
9405
9034
9373
8998
.9341
130
120
1.348
1.482
9889
10127
9863
10105
9837
10082
9811
10059
,9784
10036
9757
1~012
9730
9988
9702
9963
9674
9939
9645
9914
110
100
!,623
1.770
10335
10515
10316
10498
10296
10481
10276
10464
10255
10446
10235
10428
10214
10410
10193
10392
10171
10373
10149
10354
90
80
i.926
2.090
10670
10802
i0656
10790
10641
i0777
10626
10765
10611
10752
10596 .
10739
10580
10725
10564
10712
10548
10698
10532
10684
70
60
2.264
2.454
10913
11006
10903
i0998
10893
10989
10882
10980
10871
10971
10860
10962
10849
10953
10837
10943
10826
10933
10814
!0923
612
NFPA 12A m A92 TCR
Table A-3-1.3.1(m) Halon 1301 at 360 psig and
40 lbs/cu ft Y and Z Factors
PSIG
300
290
Z
.011
.051
0
292
1239
1
195
1146
2
98
1053
3
4
6
7
8
9
0
959
0
865
0
, 770
0
675
0
580
0
484
0
388
280
270
.094
.142
2149
3017
. 2060
2932
1970
2847
1880
2761
1790
2675
1'699
2588
1608
2501
1516
2414
1425
2326
1332
2237
260
250
.194
.251
3843
4626
3763
4550
3682
4473
3600
4396
3518
4318
3436
4240
3353
4162
3270
4083
3186
4003
3102'
3924
240
230
.313
.380
5363
6055
5292
5988
5219
5920
5147
"5852
5074
5784
5000
5715
4926
5646
, 4852
5576
4777
5505
4702
5435
220
210
.453
.532
6700
7297
6637
7240
6574
7182
6511
7123
6447
7064
6383
7004
6318
6944
6253
6884
6188
6823
6121
6762
200
190
.616
.707
7848
8353
7795
8304
7742
8256
7688
8206
7634
8156
7579
8106
7523
8056
7468 '
8004
7411
7953
7355
7901
180
170
.805
.908
8812
9228
8768
9188
8724
9148
8679
9107
8634
9066
8588
9025
8542
8983
8495
8941
8448
8899
8401
8856
160
150
1.016
1.131
9601
9936
9566
9904
9530
9872
9493
9839
9457
9807
9420
9773
9382
9740
9344
9706
9306
9671
9267
9637 '
140
130
1.251
1.377
10233
10496
10205
10471
10176
10446
10148
10421
10118
10395
10089
10369
10059
10342
10029
10315
9998
10288
9967
10261
120
110
1.508
1.646
10727
19929
10705"
10910
10683
10891
10661
10872
10638
10852
10615
10832
10592
10811
10569
10791
10545
10770
10521
10749
100
90
1.792
1.945
11105
11256
11088
11242
11072
11227
11055
11213
11038
11198
11020
11183
11003.
11168
10985
11153
10966
11137
10948
11121
80
70
2.107
2.280
11385
11494
11373
11484
11361
11474
11348
11463
11336
11453
11323
11442
11310
11431
11297"
11420
11283
11408
11270
11397
60
2.465
11586
11577
11569
11560
11551
11542
11533
11523
11514
11504
(C) SpecialFire Consideration. Where high temperatures or pressures
exist or may result from delayed system activation and for configurations other than simple pool or gas jet fires, added tests specific to the
intended appliation shall be made.
"
A-3-4.2 Halon 1301, like other halogenated hydrocarbons, chemically
inhibits the propagation of flame. However, although the presence of
Halon 1301 m the vicinity of a deep-seated fire will extinguish the
flame, thereby greatly reducing the rate of burning, the .quantity of
agent required for complete extinction of all. embers is dffficuh, to.
assess. It depends on the nature of the fuel, tts state of commmuuon,
its distribution within the enclosure, the length of time it has been
burning, the ratio of the area of the burning surface to the volume of
the enclosure, and the degree of ventilation in the enclosure. It is
usually difficult or impractical to maintain an adequate concentration
for a sufficient time to ensure the complete extinction of a deepseated fire. However, the concentration should be maintained for the
time period required to obtain response by emergen.cy personnel.
Fires in Solid Materials. Two types of fires can occur in solid fuels:
one, in which volatile'gases resulting from heating or decomposition
of the fuel surface are the source of combustion; and another, in
which oxidation occurs at the surface of, or within, the mass of fuel.
The former is commonly referred to as Uflaming" combustion, while
the latter is often called "smoldering" or "glowing" combustion. The
two t]tpes of fires frequently occur concurrently, although one type of
burmng may precede the other. For example, a wood fire may start as
flaming combustion, and become smoldering as burning progresses.
Conversely, spontaneous ignition in a pile of oily rags may begin as a
smoldering fire, and break into flames at some later point. Flaming
combustion, because it occurs in the vapor phase, is promptly
extinguished with low levels of Halon 1301. In the absence of
smoldering combustion, it will stayout.
Smoldering combustion is not subject to immediate extinguishment
as is flaming combustion. Characteristicof this type of combustion is
the slow rate of heat lossesfrom the reaction zone. Thus, the fuel
5
remains hot enough to react with oxygen, even though the rate of
reaction, which is controlled by diffusmn processes, is extremely
slow. Smoldering fires can continue to burn for many weeks, for
example, in bales of cotton and jute, and within heaps of sawdust. A
smoldering fire ceases to burn only when either all o-fthe available
oxygen or fuel has been consumed, or when the fuel surface is at too
low a temperature to react. These fires are usually extinguished by
reducing the fuel temperature, either directly by application of a
heat absorbing medium, such as water, or by blanketing with an inert
gas. The inert gas slows the reaction rate to the point where heat
generated by oxidation is less than heat losses to surroundings. This
causes the temperature to fall below the level necessary for spontaneous ignition after removal of the inert atmosphere. '
For the purposes of this standard, smoldering fires are divided into
two classes: (1) where the smoldering is not "deep seated," and (2)
dee~seated fires. The difference is only a matter of de~ree, and the
disunction is a functional one: if a 5 percent concentrauon of Halon
1301 will not extinguish it within 10 minutes of application, it is
considered to be deep seated. In practice, experiments have shown a
rather sharp dividing line ,between the two. Deep-seated fires usually
require much higher concentrations than 10 percent and much
longer soaking times than 10 minutes.
Whether a fire will become deep seated depends, in part, on the
length of time it has been burning before application of the
exunguishing agent. This time is usually called the "preburn" dme.
Underwriters Laboratories' wood crib fires (1A) and stacks of wood
allets have been readily extinguished with less than 5 percent Halon
301 maintained for less than 10 minutes following discharge. In
these tests, a 10-minute preburn was allowed. Charcoal, the ultim~tte
product of a wood fire, required over 30 minutes for complete
extinguishment in a 5 percent Halon 1301 concentration, In
charcoal fires, higher agent concentrations were found to reduce the
soaking times. At a 10 percent concentration, a 20-minute soaking
time was required, and at 20 percent, the soaking time was reduced
below 15 minutes.
~
613
NFPA 12A
A92 TCR
o
Another important variable is the fuel configuration. While wood ~
cribs and paUets are easily extinguished with 5 percent Halon 1301,
vertical wood panels closely spaced and parallelrequire about 95
percent concentrations for 3Oto 40 minutes for extinguishment.
Fires in boxes of excelsior and in piles of shredded paper also
required about 90 percent Halon 1301 for extinguishment- In these
situations, heat tends to be retained in the fuel array rather than
being dissipated to the surroundings. Radiation is an important
mechanism for heat removal from smoldering fires.
Experiments with a similar agent, Halon 1911, have shown that the
ratio of the burning surface area to the enclosure volume can affect
the concentration-soaking time requirements for some deep-seated
fires. Low area/volume ratios required higher agent concentrations
and longer soaking times than higher ratios did. In other words,
small fires in large enclosures were more difficult to extinguish than ,
the contrary situation. This suggested that, oxygen depletion is
important in the extinguishment of deep-seated fires.
To date, no firm basis has been developed to predict the agent
requirements for a deep-seated fire. In a practacal sense, however,
the use o f a Halon 130I system for control or extinguishment of a
deep.seated fire is usually unattractive. Long soaking times are
usually difficult to maintain without an extended agent discharge,
and at high agent concentrations these systems become rather
expensive. The use of Halon 1301 systems will generally be limited to
solid combustibles that do not become deep seated.
The deep-seated potential of a solid material in a given situation can
be establishedposuively only by experiment. The information given
in this standardmay assist the authority having jurisdiction in
deciding whether such experimentation is necessary.
Table A-3-4.2
~ t ~ d t y of Fuel Required to Achieve 1/2 of Lower
loslve Limit in Air at 1.0 atm. and 70*F (21°C)
Fuel Quantity,
lbs per cu ft
Material
enclosed volume
kg/m=
n-Butane
Isobutane
Carbon disulfide
Carbon monoxide
Ethane
Ethyl alcohol
Ethylene
n-Heptane
Hydrogen
.Methane
Propane
Fuel
.0014
.0016
.00099.
.0045
.0012
.0018
.0020
.0016
.00011
.0011
.0013
0.0224
0.0256
0.0159
0.0721
0.0192
0.0288
0.0320
0.0256
0.0018
0.0176
0.0256
Table A-3-4.2(a)
Development of Halon 1301 Design Concentrations
For Flame Extinguishment
Concentration in Air in Volume Percent
Safety
Average*
Factor Total
Design***
Ref**
Acetone
Benzene
Ethanol
Ethylene
Methane
n-Heptane
Propane
3.3
3.3
3.8
6.8
3.1
4.1
4.3
+0.7
+0.7
+0.8
+ 1.4
+0.7
+0.8
+0.9
=4.0
=4.0
=4.6
=8.9
=3.8
=4.9
=5.2
5.0
5.0
5.0
8.9
5.0
5.0
5.2
extinguishment'of the flames. These surface embers will normally be
extinguished by low concentrations of Halon 1301 maintained for
short periods of time.
Deep-seated fires may become established beneath the surface of a
fibrous or particulate material. This may result from flaming
combustion at the surface or from ignition within the mass of fuel.
Smoldering combustion then progresses siowly through the mass. A
fire of this kind is referred to in this standard as a deep-seated" fire.
The burning rate of these fires can be reduced by the presence of
Halon 1301, and they may be extinguished ff a high concentration
can be maintained for an adequate soaking time. However, it is not
normally practical to maintain a sufficient concentration of Halon
1301 for a sufficient time to extinguish a deep-seated fire.
Solid Surface Irtres. Almost all flammable solids begin burning on
the surface. In many materials, such as plastics without filler
materials, surface combustion is the Only type that occurs. These fires
are readily extinguished with a 5 percent concentration of Halon
1301. Although glowing embers may remain at the surface of the fuel
following extinguishment of flames, these embers will usually be
completely extinguished within 10 minutes, provided the Halon 1301
concentration is maintained around the fuel for this period of time.
It is appropriate to consider maintaining the agent concentration
a r o u n d t h e fuel until response by emergency personnel can be
achieved.
Halon 1301 Requirements for Surface F'n'es. Two basic types of
extinguishment data have been obtained for Halon 1301:
(1) Flame extinguishment data, which determine the agent
concentration necessary to extinguish a flame of a particular fuel.
(2) Inerting data, which determine the minimum premixed agent
concentration to suppress propagation of a flame front at the
"flammability peak,"or stmchiometric fuel/air composition.
Flame extinguishment data generally relate closest to the concentration actually required in a fire extinguishing system. The test
recommended for the.se measurements is the cup burner method
similar to that described in References (1), (5), and (6) (see O1-7).
Liquid fuels are examined at two temperatures:
(1) Ambient: 25"C, or approximately 5°C above ASTM open-cup
flash point of the fuel, whichever is higher, and
(9) Elevated: approximately 5°C below the boiling point of the
fuel, or 200°C, whichever is lower.
Gaseous fuels are examined at two temperatures, 25"C and 150"C.
A 90 percent safety factor is added to experimental threshold
concentrations. Design concentrations less than 5 percent Halon
1301 are not used for flame extinguishment. Measured flame
extinguishment data plus safety factor that are less than 5 percent
should be increased to a 5 percent minimum because the potential
array of fuels likely to be involved in every real fire requires the
higher concentration.
The cup burner test method has been shown to compare well with
other test methods and .with tests at larger scale. Data produced by
the cup burner is somewhat more conservative than that of tests using
conventional total flooding techniques. (See O1-7.)
(5)(6)(7)
(5)(6)(7)
(5)(6)(7)
(5)(6)(7)
(5)(6)(7)
(5)(6)(7)
(5)(6)(7)
In inerting measurements, a fuel/air mixture is contained in a test
chamber, and an ignition source is activated. If the mixture cannot
support a flame front, the mixture is considered to be nonflammable.
Typical results may be plotted as'shown in Figure A-3-4.9.1.
The normal flammability range that exists when no agent is present
is shown at the left-hand side of the graph. As Halon 1301 is added to
the sDtem, the flammability range is reduced until it finally disappears' entirely. The agent concentration at which this occurs is called
the "flammability peak" concentration. All fuel/air mixtures
containing concentrations of agent equal to or greater than the
flammability peak value are nonflammable, hence the term "inert."
*Average of values reported in references measured at elevated temperature
condittons.
**For references, see Appendtx C-I 7
***Measured exungutshmg concenlrdlloFI p]us safely tmtor are increased to a
m i n i m u m 5% for design conccntrattons
A-$-4.2.I Most materials that develop deep-seated fires do so after
exposure to flaming combustion for a certain length of time which
' varies with the material. In others, the fire may begin as deep-seated
through internal ignition, such as spontaneous heating.
The results in Table 3-4.1.1 were measured using a spherical vessel
described in Reference (3) (see C-1-7).
The choice between using the flame extinguishing concentration or
the inerting concentration for a given fuel depends on (1) the
volatility characteristics of the fuel, (9) the quantity of fuel present,
and (3) the conditions of use in the hazard. Applying Halon 1301 at
the flame extinguishment concentration to actual fires will effectively
Surface fires associated with the burning of solid materials are also
quickly extinguished by Halon 1301. In many solid materials,
smoldering combustion may continue at the surface of the fuel after
614
-
NFPA 12A -- A92 TCR
injected, the displaced atmosphere is exhausted freely from the
eficlosure through small openings or through special vents. Some
Halon 1301 is therefore lost with the ventedatmosphere, and the
higher the concentration, the greater the loss of Halon.
extinguish the fire without sacrificing the reliability of the system. It
is desirable to use this lower concentration when possible because of
the following advantages:
(1) The cost of the system wiN l~e correspond!ngly lower.
For the purposes of this standard, it is assumed that the Halon
1301/air mixture lost in this manner contains the final design
concentration of Halon 1301. This represents the worst case from a
theoretical standpoint, and provides a built-in safety factor to
compensate for non-ideal dzscharge arrangements.
(2) The concentration to which personnel will be (inadvertently)
exposed will be lower.
The danger in supplying this lower concentration is that, at some
time after extlngmshment, a flammable concentration of fuel, air,
and agent could possibly be attained through release or vaporization
of additional f u e l This is more likely with highly volatile liquid fuels,
gaseous fuels, or fuels heated to near their flash point, than it is with
high flash point liquids or solid fuels. In addition, stratification of the
evolved fuel vapors, the size and possible duratio/i of the fire, and
other materials that may become heated or involved in the fire must
be taken into account. If the volatility of the fuel can be shown to be
sumcently low, and the detection-plus-extinguishmenttime is short
enough to prevent the volatility of the fuel from reaching its flash
'
point as a result of the fire, the use of flame extinguishment data is adequate.
In addition, the extinguishing concentration may Be used if the
amount of fuel present in the hazard is too low to permit attainment
of the lower flammable limit of the fuel. The mimmum fuel quantity
required to achieve the lower explosive limit is as follows:
Fuel quantity, lbs. per 100 cu ft
enclosed volume
=
(LFL)(MW)(I.37)
T + 460
.~
,d
u:
o
,,
:~
0.a
>
LFL ffi lower flammable limit of fuel in air, er (vol)
MW = molecular weight of fuel
T =temperature,°F
.
F o r SI U n i t s
o
u.
o
ua
o.
~n
Fuel quantity kg/m a = (LFL)(MW)(4.75)
K
K = kelvin = °C + 273.15
To account for possible stratification effects that might creatd
localized explosive pockets, the fuel quantity as determined above
should be divided by an appropriate safetyfactor. Table A-5-4.2 lists
quantities for several fuels, to which an arbitrary safety factor of 2 has
• been applied. Greater safety factors may be required by individual
situations.
2O
--70
40
-40
80
120
TEMPERATURE-
°F
aoo
160
(%)
Figure A-3-5.1 Specific volume of superheated
Halon 1301 vapor (at 1 atmosphere).
I
220
.214
.208
18
,
.202
16
196
/
190
I/.~
/
.184
/
/
/
.178
ff
.172
E
I
.166
8
.154
16C
,,,8
o .148
>~ 6
~
160
"
t4.
C
a.
142
.136
2
.130
zs
/
.124
0
I
2
I
~,
;I
6
[
8
I
10
[
12
[
I/~
~ ]
16
]
18
/
/
/
/
/
118
20
VOLUHEPERCENTHALON
112
)O6
Figure A-5-4.Z1 Typical flasnmabili~/-peak presentation.
I
/
-50
A-3-5.1 Total Flooding Quantity. The volume of Halon 1301
required to develop a given concentration will be greater than the
final volume remaining in the enclosure.
-30
-I0
0
20
40
60
80
TEMPERATURE-- °C (t)
Figure A-S-5.1 (Metric) Specific volume of superheated
Halon 1301 vapor (at I atmosphere).
In most cases, Halon 1301 must be applied in a manner that
promotes progressive mixing of the atmosphere. As Halon 1301 is
615
I00
NFPA 1 2 A - A92 TCR
Table A-3-5.1
Halon 1301 Total Flooding Quantity
(1)
Temperature
-t[°F]
(2)
Haion 1301
Specific Vapor
Volume-s[ft.'/lh.]
(3)
$
- - 70
- - 60
---50
- - 40
- - 30
- - 20
- - 10
0
1.8468
1.8986
i.9502
2.0016
2:0530
2.1042
2.1552
2.2062
.0167
.0163
.0158
.0154
.0151
.0147
.0143
.0140
.0225
.0219
.0213
.0208
.0203 .
.0198
.0193
.0189
.0285'
.0277
.0270
.0263
.0256
.0250
.0244
.0239
.0345
.0336
.0327
.0319
.0311
.0303
.0296
.0289
.0407
.0396
.0386
.0376
.0366
.0357
.0349
.0341
10
20
30
40
50
2.2571
2.3078
2.3585
2.4091
2.4597
.0137
.0134
.0131
.0128
.0126
.0185
.0181
.0177
.0173
.0169
.0233
.0228'
.0223
.0218
.0214
.0283
.0277
.0271
.0265
.0260
60
70
80
90
100
110
120
130
140
150
2.5101
2.5605
2.6109
2.6612
2.7114.
2.7616
2.8118
2.8619
2.9119
2.9620
.0123
.0121
.0118
.0116
.0114
.0112
.0110
.0108
.0106
.0104
.0166
.0163
.0160
.0156
.0154
.0151
.0148
.0145
.0143
.0140
.0210
.0206
.0202
.0198
.0194
" .0190
.0187
.0184
.0181
.0178
160
170
180
190
200
3.0120
3.0169
3.1119
3.1618
3.2116
.0103
.0101
.0099
, .0098
.0096
.0138
.0136
.0134
.0132
.0130
.0175
.0172
.0169
.0166
.0164
'
~
Halon 1301 Weight Requirements
of Hazard Volume W [ib./ft?] (1) "
V
Halon 1301 Concentration -C- [% By Volume] (4)
5
6
7
8
4
W
~
[Agent Weight Requirements, (lb/ft3)] -
9
10
.0471
.0458
.0446
0434
.0423
.0413
.0403
.0394
.0536
.0521
.0507
.0~94
.0482
.0470
.0459
.0448
.0602
.0585
.0570
.0555
.0541
.0528
0515
.0504
.0334
.0326
.0319
.0312
.0306
.0385
.0377
.0369
.0361
.0354
.0438
.0429"
.0419
.0411
.0402
.0492
.0481
0471
.0461
.0452
.0254
.0249
.0244
.0240
.0235
.0231
.0227
.0223
.0219
.0215
.0300
.0294
.0288
.0283
.0277
.0272
.0267
.0263
.0258
.0252
.0346
.0340
.0333
.0327
.0320
.0315
.0309
.0303
.0298
.0293
.0394
.0386
.0379
.0371
.0365
.0358
".0351
.0345
.0340'
.0334
.0443
.0434
.0426
.0417
.0410
.0402
.0395
.0388
.0382
.0375
.0212
.0208
.0205
.0202
.0199
.0250
.0246
.0242
.0238
.0234
.0289
.0284
.0280
.0275
.0271
.0328
.0323
.0318
.0313
.0308
.0369
.0363
.0357
.0351
.0346
Pounds of agent required per cubic foot of protected volume to pro-
duce indicated concentration at temperature specified.
W
=
- -
s
100
(2) t [Temperature (°F)] - T h e design temperature in the hazard area.
(3) s [Specific Volume (ftS/lb)] - Specific volume of superheated Halon 1301 vapor may be approximated by the formula.
s = 2.2062 + .005046 t
w h e r e t = temperature, °F
(4) C [Concentration (%)] - Volumetric concentiation of Halon 1301 in air at the temperature indicated.
Table A-S-5.1 is a tabulation of the Halon 1301 weight per cuft of
hazard volume required to produce the specified concentration of
various hazard temperature conditions.
For elevations substantially below sea level, the effect is the opposite
of that described above. For those instances, the reciprocal of the
appropriate correction factor in Table A-8-8 should be used:
The initial discharge is m be completedwithin the limits specified in 3-7.1.
A-S-7.1 Rate of Application. The minimum rates established are
considered adequate for the usual surface or deep.seated fire.
However, where the spread of fire may be faster than normal for the
type of fire, or where high values or vital machinery or equipment are
involved, rates higher than the minimums may, and in many cases
should, be used. Where a hazard contains material that will produce
both surface and deep-seated fires, the rate of application should be
at least the minimum required for surface fires. Having selected a
rate suitable to the hazard, the tables and information that follow in
the standard shall be used, or such special engineering as is required
shall be carried out, to obtain the proper combination of contmner
releases, supply piping, and orifice sizes that will produce this desired
A-S-6 Effects of Altitude. At elevations above sea level, Halon 1301
vapor .e~0an.ds to a greater specific volume because of the reduced
atmospheric p.ressure. A system designed for sea-levelconditions will
meremre aevelop an actual higher concentration at elevations above sea
level. For example, a system designed to produce a 6 percent Halon 1301
concentration at sea level would actually produce an 8.7 percent
concentration if installed at 10,000 tt (5000 m) elevation. This concentration woul.d be higher than recommended for normally occuvied areas
and with egress tames longer than one minute. (See3-2.5 anc2.3-2.6,)
In order to correct for this effect, the quantity indicated at sea-level
conditions 'should be reduced for installations at higher elevations of
altitude above sea level. Correction factors are given in Table A-S-6.
rate.
616
NFPA 12A m A92 TCR
T a b l e A-3-5.1 m M e t r i c
Halon 1301 Total Flooding Quantity
Halon 1301 Weight Requirements
of Hazard Volume W [kg/m ~] (1).
V,
[°C]
Halon 1301
Specific Vapor
Volume-s[m~/kg.]
(2)
(s)
$
4
5
-50
-45
-40
-35
-30
0.11946
0.12230
0.12513
0.12797
0.13080
0.13364
0.13647
0.13931
0.14214
0, 14498
0.14781
0.15065
0.15348
0.15632
0.15915
0.16199
0.16482
0.16766
0.17049.
0.17333
0.2589
0.2529
0.2472
0.2417
0.2364
0.2314
0.2266
0.2220
0.2176
0.2133
0.3488
. 0.3407
0.3330
0.3256
0.3185
0.3118
0.3053
0.2991
0.2931
0.2874
0.4406
0.4304
0.4206
0.4113
0.4024
0.3938
0.3857
0.3778
0.3703
0.3630
0.2092
0.2053
0.2015
0.1979
0.1943
0.2819
0.2766
0.2715
0.2666
0.2618
0. 1909
0.1876
0.1845
0.1814
0.1784
0.17616
0.179O0
Temperature
-t-
-25
-20
-15
-10
-
5
0
5
10
15
20
25
30
35
4O
45
50
55
6O
65
7O
75
8O
85
9O
95
W
(1) - ~ -
0.18183
0.18467
0.18750
0.19034
0.19317
0.19601
0.19884
0.20168
Halon 1301 Concentration -C- [% By Volume] (4)
7
8
9
10
0.5343
0.5219
0.5101
0.4988
0.4880
0.4776
0.4677
0.4582
0.4491
0.4403
0.6301
0.6155
0.6015
0.5882
0.5754
0.5632
0.5515
0.5403
0.5295
0.5192
0.7279
0.7110
0.6949
0.6795
0.6648
0.6507
0.6372
0.6242
0.6118
0.5998
0.8279
0.8087
0.7904
0.7729
0.7561
0.7401
0.7247
0.7099
0.6958
0.6822
0.9301
0.9085
0.8879
0.8683
0.8495
0.8314"
0.8142
0.7976
0.7817
0.7664
0.3561
0.3494
'0.3429
0.3367
0.3307
0.4318
0.4237
0.4159
0.4083
0.4011
0.5092
0.4996
0.4904
0.4815
0.4729
0.5883
0.5772
0.5666
0.5563
0.5464 -
0.6691
0.6565
0.6444
0.6327
0.6214
0.7517
0.7376
0.7239
0.7108
0.6981
0.2572
0.2528
0.2485
0.2444
0,2404
0.3249
0.3193
0.3139
0.3087
0.3037
0.3940
0.3873
0.3807
0.3744
0.3683
0.4647
0.4567
0.4489
0.44150.4343
0:5368
0.5276
0.5187
0.5100
0.5017
0.6105
0.6000
0.5899
0.5801
0.5706
0.6859
0,6741
0.6627
0.6517
0.6410
0.1756
0.2365
0.1728
0.2328
0.1701
•0.2291
0.1675 - 0.2256
0. 1649
0.2222
0.1625
0.2189
0.1601
0.2157
0.1578
0.2126
0.1555
0.2095
0.1534
0.2066
0.2988
0.2940
0.2895
0.2850
0.2807
0.2765
0.2725
0.2685
0.2647
0.2610
0.3623
0:3566
0.3510
0.3456
0.3404
0.3353
0.3304
0.3256
0.3210
0.3165
0.4273
0.4205
0.4139
0.4076
0.4014
0.3954
0.3896
0.3840
0.3785
0.3732
0.4936
0.4858
0.4782
0.4709
0.4638
0.4569
0.4501
0.4436
0.4373
0.4312
0.5614
0.5525
0.5439
- 0.5356
0.5275
,0.5196
0.5120
0.5046
0.4974
0.4904
0.6307
0.6207
06111
0.6017
0.5926
0.5838
0.5752
0.5669
0.5588
0.5509
[Agent Weight Requirements (kg/m3)] -
6
Kilograms of agent required per cubic meter of protected volume to
produce indicated concentration at temperature specified.
s
100 - C
(2) t [Temperature (°C)] - T h e design temperature in the hazard area.
(3) s [Specific Volume (m3/kg)] - Speciflc volume of superheated ttalon 1301 vapor may be approximated by the formula:
s = 0.147 81 + . 0 0 0 5 6 7 t
where t = temperature, °C
(4) C [Concentration (%)] - Volumetric concentration of Halon 1301 in air at the temperature indicated.
A-3-7.2 Extended Application Rate. Where leakage is appreciable
and the design concentration must be obtained quickly and
maintained for an extended period of time, agent quantifies provided
for leakage compensation may be applied at a reduced rate.
discharging agent. Careful consideration of ceiling type .,and
construction, nozzle discharge characteristics, and'installation
methods is necessary. Maximum flow rates should be based on
manufacturer's recommendations.
This type of application is particularly suitable for enclosed rotating
electric apparatus, such as generators, motors, and convertors, and
also may be needed for total flooding protection of deep-seated fires.
A-4-1 Inspection. The entire fire extinguishing system should be
complefly inspected at least annually. More frequent general
inspections are recommended. Regular service contracts with the
manufacturer or installing company are recommended.
The initial discharge should be completed within the limits specified
in 3-7.1.2.
In the annual inspection, parti~lar attention should be given to the:
1. Detection and Actuation System.
A-3-8.2 Of particular concern in maintaining the integrity of the
enclosure is preventing the lifting of ceiling tiles. Clipping of ceilin~
tiles will prevent their inovemenfduring discharge. - - -
2. Agent Supply.
3. Piping and Nozzles.
For a given type of nozzle, selection of the appropriate nozzle
discharge rate ts critical to reducing the potential of damage due to
4. Auxiliary Equipment.
617
NFPA
1 2 A - - A92 T C R
In addition to the annual inspections and tests, the system should be
visually inspected periodically.
..
Altitude
Feet
3000
4000
5000
6000
7000
8000
9000
10000
11000
12000
15000
14000
15000
Meters
914
1219
1524
1829
'2134
24S8
2745
S048
3353
5658
5962
4267
4572
Correction Factor
(See Notes)
0.90
0.86
0.85
0.80
0.77
0 74
0.71
0.69
0.66
0 64
0.61
0 59
0.56
A-4-1A The charging, recharging of cylinders, or the removal or
transfer of agent should be done using a closed loop system. A closed
loop systempermits transfer of halon between supply cylinders,
system cylinders, and recovery cylinders, with only minor loss of halon
to the atmosphere.
A-4-7 Where circumstances exist that require a discharge test, test
agents sulfurhexa_fluoride or Halon 121 m a y b e used. These agents
have been identified as having characteristics similar to Halon 1301.
The discharge test is not a substitute for any of the approval tests
required in 4.7, except for the ~
test (4-7.2.1 (M)).
J
A. Planning for a Discharge Test.
1. A date and time should be set well in advance of the test m assure
that proper preparations are made.
9. To assure that the testing objectives are met, an evaluation team
should be set up, including the following: the user, the installer, and
the authority having jurisdiction.
B. Preparing for a Discharge Test
Table A-S4;
Corre.ction Factors for Altitude
I. All members of the testing evaluating team should meet and
make sure all items on the pretest inspection have been resolved.
1. Detection and Actuation System.
9. Before conducting an actual system test, read and perform all
appropriate steps in the above p r e ~ a r g e checklist. (Disregard if the
steps in the predischarge test have resulted in failures to pass tests.)
(a) The detectors should be checked (and cleaned ffnecessary) to
assure that they are free of foreign substances.
(b) If the detection system is supervised, the supervisory features
should be checked to determine that the detection system is in
satisfactory condition. The methods and procedures for this
inspection should be in accordance with the manufacturer's
recommendations.
3. The following equipment will be required for the test:
(a) An accurate concentration meter capable of providing both
direct readout and printout. Multiple recorders may be required for
large installations.
(c) Automatic actuating controls should be removed from the
containers equipped with such controls ("pilot cylindei's") and a test
made of the detection system by introducing a simulated fire
condition at one or more detectors (heat, smoke, etc., as applicable).
The actuating controls must move to the "discharged" posmon.
(b) A stopwatch.
(c) Portable exhaust fans, ffneeded for post-test ventilation.
C. Test preparation.
(d) All manual operating devices (pull boxes, manual electric
switches, etc.) should be operated with the actuating control removed
from the supply containers equipped with such controls ("pilot
cylinders"). The actuating control must move to the "discharged"
position.
1. Use of Halon 1301 as a test agent further reduces availability for
fire extinguishingpurposes. As such this standard recommends that
Halon 1301 s h o u l d n o t be used as a test agent.
9. When using SF6 the following information should be used for
guidance.
(e) All actuating controls should be reset and reinstalled after testing.
(a) Enclosure leakage rate of sulfur hexafluofide dispersed in air is
nearly identical to Halon 1301. The vapor densities of the two
materials are almost the same.
2. Containers.
(a) Containers should be examined for evidence of corrosion or
mechanical damage.
(b) Distribution in balanced piping systems is similar to that
expected with Halon 1301. THISSUBSTANCE MAYNOT BE
SUITABLE FOR TESTING HYDRAULICALLY COMPLEX SYSTEMS.
Tests to determine suitability for testing hydraulically complex
systems are ongoing.
(b) Container bracketing, supports, etc., should be checked to
determine that their condition is satisfactory.
8. Piping and Nozzles.
(a) Piping should be examined for any evidence of corrosion.
(c) Suifur hexafluoride is compatible with Halon 1301 systems
hardware.
(b) Pipe hangers and straps should be examined to see that the
piping is securely supported.
(d) The toxicity of sulfur hexafluoride is no greater than that of
Halon 1301.
(c) Nozzles should be checked to determine that the orifices are
clear and unobstructed.
(e) The dynamic loacls exerted on the piping network will be
similar to that of Halon 1501.
(d) Where nozzle seals are provided, they should be checked for
signs of deterioration and replaced if necessary.
(f) The test cylinder should be filled to 98 percent of the Halon 1301
weight to achieve the same volume percent concentration. Cylinders with
a DOT CTC rating ofS00 psig (.t~i/:ally used in 360 psig appllcations) will
not meet DOT regulations for shipping when filled with sulfur hexafluofide. However, these cylinders can b e filled with sulfur hexa_fluoride.
However, these cylinders can be filled with sulfur hexafluofide and safely
used and/or stored at the job site provided the temperature of the
cylinders is not allowed to go above 100°F.
(e) Nozzles should be checked for proper position and alignment.
4. Auxiliary Equipment.
(a) All auxiliary and supplementary components such as switches,
door and window releases, interconnected valves, damper releases,
supplementary alarms, etc., should be manually operated (where
possible) to ensure that they are in proper operaung condition.
(g) Test meters used for Halon 1301 are suitable for use with sulfur
hexafluoride. It is recommended that test thermoconductivity meters
be calibrated with a sample sulfur hexafluoride in air. If desired,
calibration with Halon 1301 can be done, but percent concentration
values must be multiplied by a factor of 2.
(b) All devices should be returned to normal "standby," condition
after testing..
618
NFPA 12A -- A92 TCR
The recording'response time of the meter when SF6 is used will be
slower than Halon ~1301.
(h) Sulfur hexafluoride is not a fire extinguishing agent.
(i) Sulfur hexafluoride ozone depletion is zero and not regulated
by the Montrefl Protocol.
3. When using Halon 121 the following information should be used
for guidance:
• (a) Because of its lower vapor density, the enclosure leakage rate of .
Haion 121 is slower than that for Halon 1301.
(b) Distribution in balanced systems is similar to Halon 1301.
Hydraulically complex systems may not be suitable for testing with
this agent.
(c) Common materials of construction are satisfactory for use with
Halon 121. However, the compatibility with exposed Buna-N seals
should be established for the duration of storage.
(d)'Seif contained breathing apparatus must be used if personnel
• enter the protected space while the agent is present. The threshold
limit value for Halon 121 is 1,000 ppm by volume.
(e) The test cylinders should be filled to 5 8 % o f the Halon 1301
wieght to achieve the same volume percent concentration.
(f) The test meter should be calibrated with a sample of Haion 121
in air. Thermoconductivity meters used to measure Halon 1301
concentrations are suitable for this purpose.
be checked for accuracy by means of a known sample. Concentration
readings should be taken at the point of the highest combustible
being protected or at a level eqmvalent to 75 percent of the height of
the enclosure, whichever is greater. The sampling points ghall not be
located less than 12 in. (305 mm) from the ceiling unless the
combustibles being protected extend within the area, in which case
special design consideration may be 'necessary. If more than one
space or compartment is being simultaneouslyprotected, a sampling
point should be located in each space in accordance with the above
criteria. (The minimum design concentration for the hazard should
be achieved at all sampling points in the enclosure within one minute
after the end of the initial discharge.) For flammable liquids and
gases, the nlinimum" specified concentration need not be maintained
for an extended period. For surface fire hazards other than
flammable liquids and.gases, 80 percent of the minimum design
concentration should be maintained for a period of 10 minutes after
the initial discharge or as required by the authority having jurisdiction. Hazards involving deep-seated combustibles require maintenance of the design concentrations for longer periods of time (see 34.2.2). Where an inerting concentration is required, a more
stringent test may be necessary. Refer to 3-4.1 to determine that
concentrations do not exceed the safety limits specified therein. 110volt, 60-cycle power should be available for operating a recordabletype analyzer. The power to the analyzer should remain on when the
fire extinguisher system is activated.
1. Haion anaiyzers should be field calibrated and adjusted, in
accordance with the analyzer manufacturer's instrucuons, prior to
each use.
2. If the system is linked to an alarm circuit providing local and
remote fire call, the appropriateparty should be notified and advised
prior to and at the completion of the test.
(g) The ozone depleting potential of Halon 121 is low (0.050 DP).
It is not regulated by the Montreal Protocol of 1987.
" 3. Actuate the system for discharge.
(h) The suitability of Halon 121 at minimum .cylinder fill densities
has not'been determined.
4. Concentration will be reported for the time period that the
authority havingjurisdicfionhas determined to be appropriate for
that particular occupancy.
(i) Halon 121 is not a recognized fire extinguishing agent.
•
*
CAUTION: There should be no smoking in or around the test
area during and after the discharge.
4. Replacement 1801 should be on hand and the replacement
containers should be weighed at 'the site.
D. Test Procedure. The following guidelines are for information
purposes only and are not intended to replace or restrict the
manufacturers' recommendations.
1. The protected enclosure should be prepared as follows:
(a) The room should be in the normal operating condition.
Taping and other nonpermanent methods should not be allowed.
(b) All openings that are to be automatically closed on system
actuation, shouldbe in their normal open position (doors, fire
dampers, etc.).
(c) All ceiling tiles should be installed.
5. The followingitems should be complied with to designate the
system as acceptable:
(a) Liquid discharge should be in accordance with 3-7-1.2.
(b) The system should achieve the specified concentration in the
protected volume within I minute after the end of the inidal
discharge.
' "
(c) The specified concentration should be maintained for the
specified holding period.
(d) The system should be properlyinstalled and perform as
designed without causing unacceptable damage to the protected
volume.
(d) All nozzle locations should be checked for obstructions. All
loose papers and light materials that may be moved by the discharge
of Haion should be removed.
6. Once the requirement for hold time has been completed,
ventilation to exhaust the Halon from the area should be started and
maintained as necessary.
(e) All areas where Halon discharge may stir up dust or debris that
could damage equipment should be vacuumed clean to minimize
potential damage.
7. Operation of all auxiliary system fuhctions, horns, lights, local
and remote alarms, magnetic releases, and so on, shouldbe
confirmed.
(f) Adjacent rooms should be checked to make sure that Haion
migrating from the room will not trip adjacent Halon systems or
affect people or equipment.
F. Failure Classification. Discharge test failure may b e classified as
one of the following:
(g) Provisions should be provided for removal of the Haion at the
end of the testing.
1. PtimaryFailum The failure of equipment necessary to complete
system discharge and achieve initial design concentration (i.e.,
hydraulic calculations, inoperative contmners, control panel
malfunction, etc.).
(h) Experience has shown that the primary cause of discharge test
failure is the inability to hold the specified concentration for the
• entire holding period. Room vacuum/pressurization techniques
should be considered for locating unwanted room leakage. These
techni.ques are highly recommended for locating room leakage both
immediately prior to a discharge test and on a future periodic .basis.
Z &amdarjFailure. The failure of ancillary equipment that does
not inhibit the system from completing discharge and achieving
initial design concentration (i.e., dampers, door closures, bells, dry
contact relays, etc.).
3. RoomIntegrityFailure. The failure of the room to hold the
specified concentration for the specified holding period.
E. Test Evaluation. For total flooding systems, a listed or approved
concentration meter should be used and calibrated in strict
accordance with the manufacturer's instructions. The meters should
619
NFPA 12A m A92 TCR
B-1.2.1.$ Halon Concentration. Special consideration should be
given to Halon 1301 systems with concentrations greater than I0
percent where the concern exists that high concentrations may result
m significant over-pressures from the discharge event in an enclosure
with minimal leakage.
G. Test Documentation. The results of the test should be documented in report form for each member of the test team. This report
should include, but not necessarily be limited to, the following:
1. A sketch of the protected area showing the location of sampling
points, in plan and elevation. '
B-1.2.1.4 Enclosure Height. Special consideration should be given to
high enclosures where the stauc pressure due to the Halon 1301
column is higher than the pressure possible to attain by means of the
door fan,
2. Copies of clearly identified analyzer chart records showing Halon
concentration. This must also include analyzer calibration results,
and the tapes should be signed by authority having jurisdiction.
B-1.2.1.5 Static Pressures. Where at all possible, static pressure
differentials (HVAC system, elevator connections, etc.) across the
enclosure envelope should he minimized d u r l n g t h e door fan test.
The test can only be relied upon for enclosureshaving a range of
static pressures outlined in B-2-5.2.3.
3. A signoffby each member of the test team..
H. Placing System Back in Service. Place the system back in service.
(Refer to the manufacturer s recommendations.)
1. Verify that all detectors and manual pull stations have been reset.
B-1.2.2 Door Fan Measurements. The following should be considered regarding the door fan and its associated measurements:
2. Refurbish or replace agent storage containers with the proper
amount of agent. Containers shouldbe weighed to verify the
required amount of agent.
B-1.2.2.1 Door Fan Standards. Guidance regarding fan pressurization apparatus design, maintenance and operation m provided by
ASTM E779-81, Standard Test Method forDetermining Air Leakage
Rate by Fan Pressurization and CAN/CGSB-149.10-M86, Determination of the Alrtightness of Building Envelopes by the Fan Depressurizafion Method.
3. Verify that the system control unit is in a normal operating
condition free of all fault indication. Normally thisis done before
arming each agent storage container release mechanism.
4. Secure the system control unit and lock where applicable.
6. Clean the area of any debris that may have resulted during the
system installation.
B-I-2.2.2 Attached Volumes. There can be no significant attached
volumes within or adjoining the enclosure envelope that will allow
detrimental halon leakage that would not be measured by t h e door
fan. Such an attached volume would be significant if it is absent of
any leakage except into the design envelope and is large enough to
adversely affect the design concentration.
7. Verify that an emergency telephone number has been leR with
the end-user.
B.I-2.2.3 Return Path. All significant leaks must have an unrestricted
return path to the door fan,
5. Verify that the end-user has been properly instructed in the use
and operation of this system.
B-1.2.2.4 Leak Location. The difficulty in determining; the 'spedfic
leak location on the enclosure envelope boundaries using the door
fan is accounted for by assuming halon leakage occurs through leaks
at the worst location, This is when one half of the total equivalent
leakage area is assumed to be at the maximum enclosureheight and
the other half is at the lowest point in the enclosure. In cases where
the below false ceiling; lea~zge area (BCI.A) is measured using section
B-2.6.2, the value attained for BCLA is assumed to exist entirely at the
lowest point in the enclosure.
Appendix B Enclosure Integrity Procedure
This Appendix is not a part of the r e q u i ~ t ~
is induded for information purposes only.
of this ~O~t'A document, but
B-1 Procedure Fundamentals.
B-1.1 Scope.
B-1.1.1 This procedure outlines a method to equate enclosure
leakage as determined by a door fan test procedure to worst case
halon leakage. The calculation method provided makes it possible to
predict the time it will take for a descending interface to fall to a
given height or for the continually mixed cases the time for the
concentration to fall to a given percentage concentration.
13-1.2.2.5 TedmlcalJndgemem. Endosures with large overhead leaks, but
no significant leaks in the floor slab and walls will yield unrealisticallyshort
retention time predictions. Experience has shown endosures of this ~/pe
maybe capable of retaining halon for prolonged periods. However, in
such cases the authorityhavingjmlsdicfion may w;aivethe quantitative
resultsin favor ofa demiled.vn~tuessedleak inspection of alIfloorsand
wallswith a door fan and smoke pencil.
B-1.1.2 Enclosure integrity testing is not intended to verify other
aspects of Halon 1301 system reliability;, i.e., hardware operability,
agent mixing, hydraulic calculations and piping integrity.
B-1.2.3 Retention Calculations. The following should be considered
regarding the retention calculations and itsassociated theory:
B-1.1.$ This procedure is limited to door fan technology. This is not
intended to preclude alternative technology such as acoustic sensors.
B-1.2.$.I Dynamic D'~hm-1~e
" Pressures. Losses due to the dynamic
discharge pressures resulting from halon system actuation are not
specificallyaddressed.
]8-1-1.4 This procedure should not be considered to be an exact
model of a discharge test. The complexity of this procedure should
not obscure the fact that most failures t o h o l d concentration are due
to the leaks in the lower surfaces of the enclosure, but the door fan
does not differentiate between upper and lower leaks. The door fan
provides a worst case leakage esumate that is very useful for enclosures with complex hidden leaks but it will generally require more
sealing than is necessary to pass a discharge teat.
B-1.2.3.2 Static Pressure. Variable external static pressure differences (wind etc.) are additive and should be considered.
B-1.2.$.5 Temperature Differences. When temperature differences
exceeding 18°F (10°C) exist between the enclosure under test and
the other side of the door fan, special considerations outlined in this
document should be considered.
/
B-1.2 Limltationa and Assumptions.
B-I.2.3A Floor Area. The floor area is assumed to be the volume
divided by the maximum height of the protected enclosure.
B-1.2.1 Halon System Enclosure. The following should be considered regarding the halon system and the enclosure:
B-1.2.3.5 Descending Interface. The enclosure integrity procedure
assumes a sharp interface. When halon is discharged, a uniform
mixture occurs. As leakage takes place, air enters the room. This
procedure assumes that the incoming air rides on top of the
remaining mixture. In reality, the interface usually spreads because of
diffusion and convection. These effects are not modeled because of
their complexity. Where a wide interface is present, the descending
interface is assumed to be the mid-point of a wide interface zone. Because of the conservatism built into the procedure, the effects of
interface spreading can be ignored. If cuntinual mechanical mixing
occurs a descending interface may not be formed see paragraph B2.7.1.6.
B-1.2.1.1 Halon System Design. This test procedure only concerns
halon total flooding fire suppression systems using Halon 1501 and
designed, installed and mamtained in accordance with NFPA 12A,
Standard on Halon 1301 Fire Extinguishing Systons. .
B-1.2.1.2 Endosure Construction. Halon 1301 protected enclosures,
absent of any containing barriers above the false ceiling, are not
within the scope of this document.
620
NFPA 12A
B-1.2.3.6 Leak Flow f~aracterlsflca. All leak flow is one-dimensional
and does not take into account stream functions.
Maximum I-Ialon Protected Height. The design height of the halon
column from the floor slab. This does not include the height of
unprotected ceiling spaces.
]3-1.2.3.7 Leak Flow Direction. A particular leak area does not have
bi-directional flow at any point in ume. Flow through a leak area is
either into or out of the enclosure.
13-1.2.3.8 Leak D i s c h ~ .
an infinitely large space.
A92 TCR
Minlmmn I-Ialon Protected Height. The minimum acceptable
height from the floor slab to which the descending interface is
allowed to fall during the retention time as specified by the authority
having jurisdiction.
The outflow from the leak discharges into
Return Path. The path outside the enclosure envelope that allows
air to travelto/from the leak to/from the door fan.
B-1.2.3.9 Leak Locations. Calculations are based on wors'tcase halon
leak locations.,
Return Path Area. The effective flow area that the air being moved
by the door fan must travel through to complete a return path back
to the leak.
B-1.2.3.10 Halon Deliver. The calculationsassume tliatthe design
concentration ofhalon willbe achieved. Ifa suspended ceilingexists,
itisassumed that,thehalon discharge willnot resultin displacement
of the ceilingtiles•Increased confidence may be obtained ifceiling
tilesare clipped within four ftof the nozzles and allperimeter tiles.
Room Pressure Gauge. The component of the door fan used to
measure the pressure differential across the enclosure envelope.
Static Pressure Difference. The pre~ure differential across the
enclosure enveloper not caused by the discharge process or by the
weight of the Haion 1301. A positive static pressure difference
indicates that the pressure inside the enclosure is greater than on the
outside, i.e., smoke would leave the enclosure at the enclosure
boundary.
B-1.3 Definitions. For the purpose of Appendix B, the following •
definitionsare to apply:
Attached Volumes. A space within or which adjoins the enclosure
envelop(e that is not protected by.halon and cannot be provided with
a clearlydefned return path:
B-2 Test Procedure.
Blower, The component of the door fan used tomove air.
]3-2.1 PrelimlnaryPreparadons. Contact the individual(s) responsible for the Halon 1801 protected enclosure and establish, obtain
and provide the following preliminary information:
Ceiling Slab. The boundary of the enclosure envelope at the
highest elevation.
Column Pressure. The theoreticalm a x i m u m positivepressure
created at the floor slab by the column of the halon/air mixture.
(a) provide a descriptioh of the test,
Descending Interface. The enclosure integri~procedure asstanesa
sharp interface.W h e n halon isdischarged,a uniform mixture occurs. As
leakage takes place, air enters the room. This procedure assumes that the
incoming air rides on top of the remaining mixture. In reality, the
interface usually spreads because of diffusion and convection. These
effects are not modeled because of their compldxity. Where a wide
interface is present, the descending interface m assumed to be the midpoint of a wide interface zone. Because of the conservatism built into the
procedure, the effects of interface spreading can be ignored. If continual •
mechanical mixing occurs a descending interface may not be formed.
See paragraph B-2.7.1.6.
Door Fan. The device used to pressurize or depressurize an
ericlosure envelope to determine its leakage characteristics.' Also
called the fan pressurization apparatus.
(b) advise the time required,
(c) determine the staff needed (to control traffic flow, set HVAC,
etc.),
(d) determine the equipment required (e.g., ladders),
(e) obtain a description of the HVAC system,
(f) establish the existence of a false ceiling space and the size of
ceiling tiles,
(g) visually determine tl~e readiness of the room with respect to the
completion of obvious sealing,
(h) determine if conflict ~dth other building trades will occur,
Effective Floor Area. The volume divided by the maximum halon
protected he!ght.
(i) determine the size of doorways,
Effective Flow Area. The area that results in the same flow area as
the existinlg, system of flow areas when it is subjected to the same
pressure difference over the total system of flow paths.
(j) determine the existence of adequate r e t u r n p a t h area outside
the enclosure envelope used to accept or supply the door fan air.
(k) evaluate other conflicting activities in and atom?, d space (e.g.,
interruption to the facility being tested).
Enclosure. The volume being tested by the door fan. This includes
the halon protected enclosure and any attached volumes:
(1) obtain appropriate architectural HVAC, and halon system
design documents.
Endosure Envelope. The floor, walls, ceiling, or roof that t o g e t h e r
constitute the enclosure.
B-2.2 Equipment Required. The following equipment is required to
test an enclosure using fan pressurization technology:
Equivalent Leakage Area. The total combined area of all leaks, '
cracks,joints, and porous surfaces that act as leakage paths through
the enclosure envelope. This is represented as the theoretical area of
a sharp ediged orifice which would exist if the flow into or out of the
entire enclosure at a given pressure were to pass solely through i t
For the purposes of this document, the ELA is calculated at the
column pressure.
B-2.2.1 Door Fan System.
B-2.2.1.1 The door fan(s) should have a total air iqow capacity
capable of producing a pressure difference at least equal to the
predicted column pressure or 10 Pa, whichever is greater.
Fan Presmalzafion Apparatus. The device used to pressurize or
depressurize an enclosure envelope to determine its leakage
characteristics. Also called the door fan.
B-2.2.1.2 The fan should have a variable speed control or a control
damper in series with the fan.
B-2.2.1.3 The fan should be calibrated in air flow units or be
connected to an air flow metering system.
Floor Slab. The boundary of the enclosure envelope at the lowest
elevation.
B-2.2.1.4 The accuracy of air flow measurement should be ± 5% of
the measured flow rate.
Flow Pressure Gange. The component of the door fan used to
measure the pressure difference across the blower to give a value
used in calculating the flow into or out of the enclosure envelope.
B-2.2.1.5 The room pressure gauge should be capable ofmeasurlng
pressure differences from 0 Pa to at least 50 Pa. It shbuid have an
accuracy of ±1 Pa and divisions of 2 Pa or less. Inclined oil-filled
manometers are considered to be traceable to a primary standard and
Haion Protected Enclosure. The volume protected by the Halon
1301 system.
621
,
NFPA 12A m A92 TCR
B-2.2.8.6 Create a sharp edged, round or square opening in the rigid
material. The area of this opening should be at least 33 percent o f
the initial ELA measured. Typical opening sizes a/e approximately
.05, 0.1, and 0.9 meters squared, depending on the initial leakage of
the enclosure. Adjust the blower to the previously used positive or
negative pressure differential. Measure the flows and calculate an
average ELA value using Section B-2.6.3.
need not be calibrated. All other pressure-measurement apparatus
(e.g., electronic transducer or magnehelic) should be calibrated at
least yearly.
B-2.2.1.6 Door fan systems should be checked for calibration every 5
years under controlled conditions and a certificate shall be available
for inspection at all integrity tests. The calibration shall be performed according to manufacturers specifications.
.
B-2.2.S.7 Field calibration is acceptable if the difference between the
first and second ELA value is within ± 15% of the hole area cut in the
rigid martial. If the difference in ELA values is greater than ± 15%',
the door fan apparatus should be re-calibrated according to the
manufarturerrs recommendations and either ASTM E77O~81 or
CAN/CGSB-149.10-M86.
The certificate shall include the following:
(a) Description of calibration facility and responsible technician.
(b) Date ofcalibratlon and serial n u m b e r of door fan.
B-2.$ Initial Endosure Evaluation.
(c) Room pressure gauge error estimates at 8, I0, 19, 15, 90 and 40
Pa measuredby both ascending and descending pressures (minimum).
B-2.S.1 Inspection.
(d) Fan calibration at a minimum of 3 leakage areas (approximate):
0.5, 0.25, and 0.05 sq m measured at a pressure of I0 Pa.
B-2.3.1.1 Note the areas outside the enclosure envelope that will be
used t o supply or accept the door fan air.
B-2.2.1.7 A second blower or multiple blowers with flex duct and
panel to flow to above ceilings spaces is optibnal.
B-2.2.2 Accessories. The following equipment is also useful:
B-2.5.1.2 Inspect all openable doors, hatches, movable partitions for
their ability to remain shut during the test.
,
B-2.$.1.$ Obtain or generate a sketch of the floor plan showing walls,
doorways and the rooms connected to the test space. Number or
name each doorway.
(a) smoke pencil, fully charged, (see Caution)
CAUTION: Use of cherriically generated smoke as a means of
leak detection may result in acuvatlon of building or. halon
system smoke detectors. Appropriate precautions should be
taken. Due to corrosive nature of the smoke, it shall be used
sparingly.
B-2.3.1.4 Look for large attached volumes open to the test space via
the floor or walls of the test space. Note volumes and apparent open
connecting areas.
B-2.3.1.5 Check floor drains and sink drains for traps with liquid.
(b) bright light source,
B-2.3.2 Measurement o f Enclosure.
(c) floor tile lifter,
B-2.3.2.1 Measure the halon protected enclosure volume. Record all
dimensions. Deduct the volume of large solid objects to obtain the
net volume.
(d) measuring tape,
(e) masking or duct tape,
B-2.3.2.2 Measure the highest point in the halon protected enclosure.
(f) test forms,
(g) multi-tip screwdrivers,
B-2.$.2.3 Calculate the effective floor area by dividing the net halon
protectedvolume by the maximum halong protectedenclosure height.
(h) shop knife or utility knife,
B-2.8.3 Preparation.
(i) several sheets of thin plastic and cardboard,
B-2.$.8.1 Advise supervisory personnel in the area about the details
of the test.
(j) doorstops,
B-2.8.$.2 Remove papers and objectslikelyto be affectedby the air
currents from the discharge of the door fan.
(k) signs to post on doors that say"DO NOT SHUT--DOOR FAN
TEST INPROGRESS" or ~DO NOT OPEN--DOOR FAN TEST IN
PROGRESS".
~2.3.3.3 Secure alldoorways and openings as for a halon discharge.
Post personnel to ensure they stagyshut/oopexn . O pen doorways inside
halon protected enclosure even though they may be closed upon
discharge.
(1) thermometer.
B-2.2.8 Field Calibration Check.
B-2.3.8.4 Get the user's personnel a n d / o r the halon contractor to set
up the room in the same state as when a discharge would occur, i.e.,
HVAC shut down, dampers closed, etc. Confirm that all dampers and
closeable openings are m the discharge mode position.
B-2.2.3.1 This procedure enables the authority having jurisdiction to
obtain an indication of the door fan and system calibration accuracy
upon request.
i
B-2.2.3.2 The field calibration check should be done in a separate
enclosure. Seal offany HVAC re~sters and grilles if present. Install
the door fan per manufacturer's instructions and section B-2.4.
Determine ira static pressure exists using section B-2.5.2. Check
openings across the enclosure envelope for airflow with chemical
smoke. If any appreciable flow or pressure exists, choose another
room or eliminate the source.
B-2.4 Door Fan II~tAIlatlOT M
B-2.4.1 The door fan apparatus generally consists of a single door
fan. A double or multiple door fan for larger spaces or for neutralizing leakage through a suspended ceiling may be used for certain
applications.
B-2.4.2 Set up one blower unit in the most convenient doorway
leading into the space. Choose the doorway which opens into the
largestreturn path area. Consideration must be given to individuals
requiring accessinto or out of the facility.
B-2.2.3.3 Install a piece of rigid material less than 1/8 in. thickness
(free of any penetrations) in an unused blower port or other
convenient enclosure opening large enough to accept an approximately 0.01 sq meter sharp edge round or square op-ening.~-
B-2.4.8 Follow the manufacturer's instructionsregarding setup.
B-2.2.3.4 Ensure that the door fan flow measurement system is
turned to properly measure pressurization or depressurization and
operate the blower to achieve a convenient pressure differential,
preferably 10 Pa.
B-2.4.4 Examine the sealing around the door (before door fan
installation) that the door fan will be mounted in to determine if
significant leakage exists. If significant leaks'are found they should be
corrected. If the manufacturers stated door fan sealing system
leakage is less than the apparant remaining leakage o f the doorway,
the difference must be added to the leakage calculated in section B9.6 (see B-2.6.3.5).
B-2.2.3.5 At the pressure achieved, measure the flow and calibration
an initial ELAvalue using B-2.6.3. Repeat the ELA measurement
under positive pressure and average the two results.
622
NFPA 12A -- A92 TCR
B-2.4.5 Ensure all pressure gauges are leveled and zeroed prior to
connecting them to the fan apparatus. This should be done by first
gently blowing into or drawing from the tubes leading to the pressure
gauges so the needle fluid or readout moves through its entire span
Arid stays at the maximum gaulge readinjg for 10 seconds. This
confirms proper gauge operauon. If using a magnehelic gauge,
gendy tap the gauge face for 10 seconds. With both .p~ortsof each
gauge on the same side of the doorway (using tubes ffnecessary),
zero the gauges with their particular adjusting method.
(d) Ifhalon is designed to discharge above the false ceiling, remove
1 percent of the ceihng tues.
(e) Remeasure the static pressure (Psr) at the time of the door fan
test, between the room (not below the false floor) and the return
path space.
(f) Make every effort to reduce the static pressure (PsT) by shutting
down air handling equipment even though it may operate during
discharge.
]3-2.4.6' Connect the tubing for the room pressure gauge. Ensure'the
tube is at the floor slab elevation and extends at least 10 feet away
from the outlet side of the door fan blower, away from its air stream
path and away from all significant air streams (i.e., HVAC air flows or
openings where airflow could impinge on the tube).
13-2.4.7 The door fan should be arranged to alternately blow out of
(depressurize) and blow into the space (pressurize). Both measurements should be taken as described in Section 13-2.6.
B-2.5 Door Fan Enclosure Evaluation.
. B-2.5.1 Pressure Runup Inspection.
B-2.5.1.1 Activate the blower and adjust the enclosure pressure to
negative 15 Pa or maximum negative achievable (up to 15 Pa).
(g) Record Psr determine its direction using smoke or other means.
(h) Record the position of each doorway, open/shut.
(i) If the static pressure fluctuates due towind, use awind .d.a~.
n..jsing
' system incorpora6ng 4-averaging tubes on each dde of the building to
eliminate its effects. The CAN/CGSB-149.10-1986 standard may be used.
) I r a subfloor pressurization airhandler cannot be shut down for
e test and leaks exist in the subfloor, these leaks may not be
daccurately
measured. Every attempt must be made to reduce subfloor
leaks to insignificance. During the test as many floor tiles as possible
should be lifted to reduce the amount of subfloor pressurizanon.
Note that under such conditions the Suspended CeiLing Leakage
Neutralization Method will be difficult to conduct due to massive air
turbulance in the room.
B-2.5.1.2 Inspect all dampers with smoke to ehsure they are closing
properly. Record problems and notify individuals responsible for the
"enclosure of the problems•
B-2.5.1.$ Inspect doors and hatches to ensure correct closure.
Record problems and notify individuals responsible for the enclosure
of the problems.
CAUTION: The removal of raised floor tiles creates a serious
safety hazard. Appropriate precautions shall be taken.
B-2.6.I.$ Calculate the column pressure in the halon protected
enclosure using the following equation:
Pc = ( g ) ( H o ) (r,. - ro)
(1)
B-2.5.1.4 Inspect the wall perimeter (above and below the falsefloor)
and the floor slab for major leaks.Note location and sizeof major
leaks. Track down major airflow currents.
Where:
pc
g
B-2.5.2 Static Pressure Measurement.
Ho
r,,
13-2.5.2.1 Seal the blower opening with the door fan properly
installed but without the blower operating. Observe the room
pressure gauge for at least 30 seconds. Look for minor fluctuations in
pressure..
B-2.5.2.2 Under pre-haion discharge conditions, measure the worst
case (greatest) pressure differential(Ps.) across a section of envelope
containing the largest quantity of leaksexpected to leak haion. If the
, subfloor is pressurged at discharge, measure the differential between
the subfloor and outside the envelope. Call this value Psfi (for static
at halon discharge). Determine the flow direction with smoke or
other indicating method.
B-2.5.2,$ If the static pressure (PsH) has an absolute value greater
than 25 percent of the column pressure calculated in B-2.6.1.3 it must
be permanently reduced. Large static pressures decrease the level of
certainty inherent in this procedure. The most common causes of
excessive static pressure are leaky dampers, ducts and failure to shut
down air handhng equipment serving the enclosure.
B-2.5.4 Record the position of all doorways, whether open or shut,
when the static pressure (PsQ.Was measured.
ro
= P r e s s u r e d u e to t h e h a l o n c o l u m n ( P , )
= A c c e l e r a t i o n d u e to g r a v i t y (9.81
M/se&)
•
= Height of protected enclosure (m)
= H a l o n / a i r m i x t u r e d e n s i t y ( k g / m a,
see e q u a t i o n 8)
= A i r d e n s i t y ( 1 . 2 0 2 k g / m 3)
If the calculated column pressure is less than 1.0 Pa, use 10 Pa as the
column pressure.
B-2.6.1.4 Depressurize the enclosure with a door fan blower(st till
the measured pressure differential reading on the gauge (P=) goes
through a total pressure reduction (dP~) equal to the column
pressure (Pc)" As an example, if the stauc pressure (PST) measured in
B-2.6.1.2 was -1 Pa, and the calculated column pressure is 10 Pa, blow
air out of the room until a P of-11 Pa is obtained. If the static
pi'essure (P,T) was + 1 Pa, an~ the calculated column pressure is 10
Pa, blow air-out of the room until a P of-9 Pa is obtained If using
magnehehc gauges, tap both the room pressure and flow pressure
gauges for lOseconds each. Wait a further 30 seconds before taking
the readings.
•
m
"
B-2.6.L5 Measure the airflow (Q~) required to obtain the pressure
reduction (dP=) required. It is in~portant to ensure manufacturer
instructions ar~ followed to ensure that air flow is accurately
measured with respect to direction of flow
]3-2.6 Door Fan Measurement.
B-2.6.1 Total Enclosure Leakage Method.
B-2.6.1.1 This method determines the Equivalent Leakage Area of
the entire enclosure envelope. It is determined by measuring the
enclosure leakage under both positive and negative pressures a n d
averaging the readings. This approach is u s e d i n order to minimize
the influence of static pressures on the ELA calculation.
B-2.6.1.2
B-2.6.1.6 The pressure reduction generated dP m may be up to 30%
greater, but now lower in absolute value than the calculated 'column
pressure.
B-2.6.1.7 Repeat paragraphs B-2.6.1.4 through B-2.6.1.6 while
pressurizing the enclosure. As an example, ff the static pressure (Psr)
measured in B-2.6.1.2 was -1 Pa, and the calculated column pressure- .
is 10 Pa, blow air into the room until +9 Pa is obtained. If the static
pressure was +1 pa, and the calculated column pressure is 10 Pa, blow
air in to the room until +11 Pa is obtained.
(b) Ensure adequate remm path area is provided to allow an unrestricted return airflow path back to the door fan from enclosure leak&
B-2.6.1.8 Ensure that the door fan flow measurement system is
actually turned around between tests to properly measure pressurization or depressurization, and that the motor rotation is not simply
reversed. Ensure that the airflow entering the room is not deflected
upwards which may cause lifting of any existing ceiling dies.
(c) Remove 1 percent of the floor files (for false floors) if an
equivalent area is not already open.
13-2.6.1.9 Measure the air temperature within the enclosure ('ix) and
outside the enclosure (To).
(a) Block open all doorways around the enclosure and post
personnel to ensure they stay open.
623
NFPA.12A -- A92 TCR
B-2.6.2 Suspended Ceiling Leakage Neutralization Method (Optionai).
B-2.6.3.3 The airflow should be corrected for temperature if the
difference between the temperature of the air being blown through
the door fan and the temperature of the air going into or out of the
B-2.6.2.1 When an unobstructed suspended ceiling exists, the
leakage area below the ceiling may optionally be measured by
neutralizing ceiling leaks. This method may provide a more accurate
estimate ofhalon leakage rates. This method should not be used if
the walls between rooms within the zone are sealed at the ceiling slab.
This method cannot be used when the halon system is designed to
protect above this suspended ceiling. This test method does not
anply that leakage above the suspended ceiling is acceptable. This
technique may be difficult or impossible to perform under the
following conditions:
leaks during the door fan test exceeds 10°C (18°F). If this condition
exists, correct the flows as follows:
= (Q~) [(TL + 273)/ ( T v + 273)] .5
Where:
Q~ = C o r r e c t e d flow (m3/s)
O~ = U n c o r r e c t e d flow (m3/s)
TL = T e m p e r a t u r e of air going t h r o u g h r o o m leaks ( ° C )
T v = T e m p e r a t u r e of air g o i n g t h r o u g h d o o r fan ( ° C )
(a) Air movement within the room may make it difficult to observe
neutralization, pardcularly in small rooms.
NOTE: When depressurizing, when pressurizing
T, = T ^ . =T.
(b) Obstructions above the suspended ceiling i.e., beams, ducts,
and partitions may make it difficult to obtain uniform neutralization.
(c) Limited clearance above the suspended ceiling e.g. less than
one ft, may make it difiScult to-obtain neutralization.
B-2.6.2.2 If not aiready done, obtain the Equivalent Leakage Area of
the halon protected enclosure using the total enclosure leakage
method in section 13-2.6.1.
B-2.6.2.$ Ceiling level supply registers and return grilles may be
temporarily sealed off to increase the accuracy of this method. If
sealed Psr should be remeasured.
(2)
B-£.6.$.4 For equation (2), corrections for barometric pressure are
not necessary since they cancel out, and corrections for humidit], are
too small to be of concern. No other correcdons apply. Ifequaaon
(2) is not used, then Q¢ = Q,.
B-2.6.3.5 After measurements are taken from pressurizing and
depressurizing the enclosure, the leakage area in each direction
should be caiculated,'and the results should be averaged. Each
leakage area is calculated assuming the density of air ts 1.202 kg/m s
and the discharge coefficient for a hole in a flat plate (door fan) is
0.61. The equauon is:
NOTE: Temporary sealing of such openings is not permitted
when conducting a Total Enclosure Leakage Test.
1.271 Qc
A -
B-2.6.2.4 Install two separate door fans or a multiple blower door fan
with one blower ductedto the above suspended ceiling space and the
other into the room space below the suspended ceiling. It is not
necessary to measure airflow through the upper fan.
Pm
(3}
PSy
"[
I
Where:
=
A
=
m =
]8-2.6.2.5 Depressurize above and below the suspended ceiling by
adjusting two separate blowers till the required pressure reduction
and suspended ceiling leak neutralization (i.e., no airflow through
the suspended ceiling) is achieved.
Area of leaks (mS).
Door fan flow, corrected (mS/S)
Door fan pressure for Q~ 9Pa)
The final value for A is determined by averaging the areas obtained
under both a positive and negative pressure.
Leaks are neutralized when at opened locations in the suspended
ceiling smoke does not move up or down when emitted within 1/4 in.
of the openings. If neutralization is not possible at all locations,
ensure either smoke does not move or moves down (but not up).
Choose undisturbed locations away from flex duct flows, airstreams
and lighting fixtures because local air velocities make neutralization
difficult to detect.
]3-2.6.3.6 Equation (3) should be used for both the total enclosure
leakage method (section B-2.6.1) and the optional suspended ceiling
leakage neutralization method (section B-2.6.2). For section 13-2.6.1,
the area of leaks (A) equals the equivalent leakage area (ELA). For
section 13-2.6.2, the area of leaks (A) equals the below ceiling leakage
area (BCLA).
B-2.6.2.6 Measure the airflow (Q~) through the fan which is
depressurizing the volume below the false ceiling to obtain the
pressure reduction (dPm) required.
I]-2.7 Retention Calculation.
B.2.7.1 Calculation.
]3-2.6.2.7 The pressure reduction generated in the volume below the
false ceiling may be up to 30% greater, but not lower in absolute valve
than the calculated column pressure.
B-2.7.1.1 Total Leakage Area, Calculate the total leakage area (A.r)
using the equivalent leakage area (ELA) determined from the door
fan measurements as per B-2.6.3. This should be based on a
discharge coefficient of 0.61 that is used with the door fan apparatus.
The following equation applies:
]3-2.6.2.8 Repeat paragraphs B-2.6.2.5 through B-2.6.2.7 while
pressurizing the enclosure except, either smoke does not move or
moves up but not down.
Ar
B-2.6.2.9 An alternate method for measuring the below ceiling leaks
consists of temporarily sealing identifiable ceiling level leaks using a
flexible membrane, such as polyethylene sheet and tape, and then
measuring the below ceiling leakage solely using door fans drawing
from the lower part of the room. No flex duct is needed. Examples
of sealable leaks are undampered ceiling level supply registers or
return grills, or an entire suspended ceiling lower surface.
= ( E L A ) * 0.61
(4)
Where:
Ar
= T o t a l leakage a r e a (m 2)
E L A = E q u i v a l e n t l e a k a g e a r e a (m 2)
B-2.7.1.2 Lower Leakage Area. If the leakage area is measured using
only section B-2.6.I, Total Enclosure Leakage Method, then equation
(5) should be used to calculate the lower leakage area (AI.L). If the
below ceiling leakage area (BCLA) is measured using sectaon B-2.6.2,
Suspended CeilingNeutralization Method, then equation (6) applies
instead. These equations are:
B-2.6.$ Equivalent Leakage Area Calculation.
B-2.6.$.1 Section 13-2.6.3 outlines the door fari calculation to be used
in conjunction with sections B-2.6.I and ]3-2.6.2
ALL = AT/2
B-2.6.3.2 The leakage area is generally derived per CAN/CGSB149.10- M86. The CGSB document calculates area at 10 Pa only
whereas this procedure calculates area at a minimum of I0 Pa but
allows for calc-ulation at the Halon Column Pressure which could be
greater than 10 Pa.
ALL = ( B G L A ) * 0.61
(5)
,
Where:
ALL
= L o w e r leakage a r e a ( m 2)
B C L A = B e l o w ceiling leakage a r e a (m z)
624
(6)
NFPA 12A -- A92 TCR
B-2.7.1.3 Leak Fraction. Determine the lower leak fraction (IRA)
using the following equation:
FA = ALL/AT
Where:
FA =
ffi Static pressure (Pa)
= Exl~onent value (0.5)
= Hetght of ceiling (m)
Height of interface from floor (m)
~o
(7)
]8-2.7.2 Acceptance Crlteri& The time (t) that was calculated in
paragraph B-2.7.1.7 must equal or exceed the holding time period
specified by the authority having jurisdiction per paragraph 4-7.2.2.
Lower leak fraction
B-2.7.$ Sample Calculation.
B-2.7.$.1 General. This section provides an example of leakage area
calculations and retention calculations. Door fan measurements
using the total enclosure leakage method (section B-2.6.1) and the
optional suspended ceiling leakage neutralization method (section B2.6.2) are both considered.
I r F^ is > 0.05 make Fi = 0.05
B-2.7.1.4 Halon Mixture Density. Calculate the density of the Halon
1301/air mixture (r=) using the following equation:
r= = [(6.283)(c/100)] + [(r.)(100-c)/1O0]
(8)
B-2.7.$.2 Enclosure and System Data. The following data regarding
the enclosure and the halon system is provided:
Where:
r,. = H a l o n / a i r m i x t u r e d e n s i t y ( k g / m 3)
r. = A i r d e n s i t y (1.202 k g / m 3)
c
= H a l o n 1301 c o n c e n t r a t i o n ( % )
B-2.7.1.5 Static Pressure. Determine the correct value for (PsH) to be
used in equation (10); if the (Psn) recorded is negative let it equal
zero (0), if it is positive use the i"ecorded value.
(a) inidal Halon 1301 concentration (c): 6.0%
(b) volume ofhaion protected enclosure (V): 153.2 m s
(c) ileight ofhalon protection enclosure (Ho): 2.7 m
(d) calculation static pressure measurement (Pro): -2.0 Pa (perB-
2.5.2.2; smokeflows into room)
]3-2.7.1.6 Minimum Height. Determine from the authority having
jurisdiction the 'minimum height from the floor slab (H) that is not to
be affected by the descending interface during the holding period.
(e) door fan static pressure measurement (PsT): -1.0 Pa (perB-
2.6.1.2; smok~flows into room)
If continuous mechanical mixing occurs during the retention time
such that a descending interface does not form and the halon
concentration is constant throughout the protected enclosure,
calculate an assumed value for H based on the initial and final
specified concentrations using the following equation:
(f) temperature inside T l enclosure: 18°C
(g) temperature outside T o enclosure: 20°C
(h) minimum acceptable halon height (H): 2m (perB-2.7.1.6)
H ~_~_ x H o
C
B-2.7.$.$ P r e l l m | n a r y Calcu]a~on~
Where:
B-2.7.$.3.1 Calculate the effective floor area (perB-2.3.2.3):
H
= Assumed value for H for mixing calculation
== Actual Haion 1301 concentration ( % )
Final Halon concentration per authority having
juri~iction re q.uirement.
H o = Mammum Halon Protected Height
At
enclosure (P:) using equation (1) (perB-2.6.1.3). Equauon 1 requires
that the halon/air mixture density (rm) be known. Thus, the hal-on/
air mixture density (r=) is first calculated using equation (8) (per B2.7.1.4) as follows:
r=
= [(6.283)(6/100)] + [(1.202)(100-6)/100]
= 0.377 + 1.130
= 1.507 kg/m s
Pc,
= (9.81) (2.7) (1.507 - 1.202)
ffi 8.1 Pa
P, < 10 Pa; therefore Pc = Pa per B-2.6.1.3.
B-2.7.1.7 Time. Calculate the minimum time (t) that the enclosure
is expected to maintain the descending interface above (H), using
the following equations:
C4 = 2(P,)/r,,
(158.2)/(2.7) = 56.7 m ~
B-2.7.$.$.2 Calculate the column pressure in the halon protected
Example: H o = 4m, initial concentration = 7%, final = 5%, H = 5/7
X 4m = 2.86m. Ensure mixing is not created by ductwork which leaks
excessively to zones outside the enclosure.
Ca = 2.(rm - r°)(g)/ {rm + IFa/(1-FA)]'/N(r,)}
=
(9)
(8)
(1)
B-2.7.3.$.3 Determine the ta~. et depressurization pressure range (per
B-2.6.1.4 and B-2.6.1.6) for taking door fan measurements.
(10)
Dep. Target Pres. = -1 -10 = -11 Pa -1 + (-10 X 1.3)
t = A . [ ( C a ( H o ) + C 4 '-N - ( C a ( H ) +C,)'-NI
,/I(1-N)(Ca)(Fa)(Ar)]
(11)
B-2.7.$.3.4 Determine the target pressurization pressure range (perB2. 6.1.7) for taking door fan measurements.
Where:
t
T i m e (seconds)
C3 = C o n s t a n t for e q u a t i o n s i m p l i f i c a t i o n
C4 = C o n s t a n t for e q u a t i o n s i m p l i f i c a t i o n
An = R o o m floor a r e a ( m 2)
g = A c c e l e r a t i o n d u e to g r a v i t y (9.81 m / s e C )
P s = Static p r e s s u r e (Pa)
N = E x p o n e n t v a l u e (0.5)
H o = H e i g h t of ceiling (m)
H = H e i g h t of interface f r o m floor (In)
Press. Target Pres. ffi -1 + 1 0 ffi +9 Pa to -1 + (10 X 1.3)
B-2.7.$.4 Total Enclosure Leakage M e t h o d .
B-2.7.$.4.1 Leakage Area Calculation.
(a) Depressurize the enclosure into the -11 Pa to -14 Pa range with
the door fan. Measure the airflow required and pressure created (per
B-2.6.1.4, .Sand.6).
Q, ffi0.2046 mS/sec (depressurizing to -12 Pa)
(b) Pressurize the enclosure into the +9 Pa to +12 Pa range with the
door fan. Measure the airflow required and pressure created (per B-
Where:
t
Cs
=
=
g
=
2.6.1.7)
Time (seconds.)
Constant for equation simplification
Constant for equation simplification
Room floor area ( m 2)
Acceleration due to gravity (9.81 m/sec =
625
NFPA 12A -- A92 TCR
Q~ = 0.3480 cu m/sec (pressurizing.to +10 Pa)
(c) Pressurize the enclosure below the ceiling with the door fan into
the +9 Pa to +12 Pa range. Measure the airflow required and the
pressure created (per B-2.6.2. 8):
(c) Correct the door fan airflow for the temperature difference
between the inside and outside enclosure temperatures (per B2.6.3.3). This correction is not necessary ff the temperature
difference is less than 10°C (18°F) and is not needed for these sample
calculations; however, it is included herein for demonstrative
purposes. Using equation (2), this correction is:
Qu = .0871 mS/sec (pressurizing to +10 Pa)
(d) Correct the door fan airflow for the temperature difference
between the inside and outside enclosure temperatures ~ B-26.3.3). This correction is not necessary if the temperature difference
is less than 10°C (18°F) and is not needed for these sample calculations; however, it is included herein for demonstrative purposes.
Using equation (2), this correction is:
Depressurization
Q,
= (.2046) [(20 + 273)/(18 + 273)] 's = .2053 cu m/sec
(2)
Pressurization
Q¢
ffi ( . 3 4 8 0 ) [ ( 1 8 + 2 7 3 ) / ( 2 0
+ 2 7 3 ) ] 's =
.3468 cu m/see
(2)
(d) Calculate the leakage area (A) from the door fan measurements
(perB-2.6.3.5). Using equation 3, the calculations are:
Depressurization
'
A = (1.271) (.2053)/[1-121/1-1231 - 11/1'-1"s)1]
A = (1.271) (.2053)/112.311 = 0.1059 sq m
(3)
Pressurization
A = (1.271) (.3468)/[1101/110 "s - bll/b1.Sl]
A = (1.271) (.3468)/110 "s + 11 = 0.1059 sq m
(3)
Pressurization
Q¢ = (.0871)) [(18 + 273)/(20 + 273)] "5 ffi .0868 cu m/sec~
(2)
A = (1.271) (0.514)/([1-121/-12'Sl - 1-11/1-1-s)1]
A ffi (1.271) (0.514)/([12.s-11=0.0265 sq m
A ffi (1.271) (.0868)/([1101~.0.Sl. M l / l - l . S l ]
A = (1.271)
(.0868)/([110
"~ + 11 =
(3)
0.0265 sq m
Average
A = (0.0265 + 0.0265)/(2)
= 0.0265 m s
BCLA = A = 0.0265 m s
Calculation
B-2.7.3.5.2
(a) Calculate the total leakage area (AT) using equation (4) (perB-
Retention
Calculation.
(a) Calculate the total leakage area (AT) using equation (4) (perB-
2.7.1.1):
2.Zl.I):
A, r = (.1059) (.61) = .0646 sq m
(4)
AT
= (.1059) (.61)
= .0646 m =
(b) Calculate the lower leak area (ALL) using equation (5) (per B-
2.7.1.2):
ALL = ( 0 . 6 4 6 ) / ( 2 )
(3)
Pressurization
ELA = A = 0.1059 sq m
Retention
(2)
(e) Calculate the leakage area (A) from the door fan measurements
(per B-2-6.3.5). Using equation 3, the calculations are:
Average
A = (0.1059 + 0.1059)/(2) = 0.1059
B-2.7.3.4.2
Depressurization
Q: = (.0512) [(20 + 273)/(18 + 273)]'5 = .0514 cu m/sec
=
.0323 sq m
(b) Calculate the lower leakage area (ALL) using equation (6) (per
B-2.ZI.2):
(5)
ALL
(c) Calculate the leak fraction (F^) using equation (7) (per B-2.7.1.3)
F^ = (.0323)/(.0646) = 0.5
= (2)(1.507 - 1.202) (9.81)
/{1.507 + [.5/(1 - .5)] TM (1.202)}
ffi 2.2090
C4=0 = 2(0)/1.507
(7)'
(6)
(c) Calculate the leak fraction (FA) using equation (7) (perB-
2.7.1.3):
FA
(9)
= (0.0161)/(0.0646)
= 0.2492
(7)
( d ) Calculate the constants for equation simplification (C. and C , )
using ec)uations (9) and (10) (po'B-2. 7.1.7). Since the vaiu~ for (PsH)
is negauve, it is set equal to zero (per/3-2. 7. I . ~ . The calculations are:
(10)
C3
(e) Calculate the minimum time (t) that the enclosure is expected
to maintain the descending interface using equation (11) (per B-
2.7.1.7):
t = 56.7[(2.2090(2.7)
+ 0) 1"s
- (2.2090(2) + 0) l's]
= (0.0265) (.61)
= 0.0161 m ~
(d) Calculate the constants for equation simplification (Cs and C4)
using equations (9) and (10) (perle2. 7.1.7). Since the value for (PsH)
is negauv'e, it is set equal to zero.(per B-2. 7.1.~. The calculations are:
Cs
(4)
C4
(
= (2)(1.507 - 1.202)(9.81)
/ { 1 . 5 0 7 + [.2492/(1 - . 2 4 9 2 ) ] ''°5 ( 1 . 2 0 2 ) } `9)
= 3.6502
= 2(0)/1.507
(10)
=
(11)
0
(e) Calculate the minimum time (t) that the enclosure is expected
to maintain the descending interface using equation (11) (perB-
/ [(1- .5) (2.2090) (.5) (.0646)]
= 56.7 (0.3403)/(0.0357)
= 540 seconds = 9.0 minutes
2.7.1.7):
t
]3-2.7.3.5 Suspended Ceiling Leakage Neutralization Method
(optional).
B-2.7.3.5.1 Leakage Area Calculation.
(a)" Determine the equivalent leakage area (ELA) for the total
enclosure as described previously in section 13-2.7.3.4.1. The result is:
= 5 6 . 7 [ ( 3 . 6 5 0 2 ( 2 . 7 ) + 0) ~-5
5]
- (3.6502(2) + 0)'/ [(1 - . 5 ) ( 3 . 6 5 0 2 ) ( . 2 4 9 2 ) ( . 0 6 4 6 ) ]
= 56.7 ( 0 . 4 3 7 4 ) / ( 0 . 0 2 9 4 )
= 840 s e c o n d s = 14 m i n u t e s
(11)
S a m p l e Calculation Reaulta. The minimum time (t) that
the enclosure ts.expected to maintain the descending interface above
height (H) is 9 minutes using the Total Enclosure Leakage Method
a n d l 4 minutes using the optional Suspended Ceiling Leakage
Neutralization Method. Both of these predictions are conservative
and the actual time is expected to be greater than these values.
Because the optional Suspended Ceiling Leakage Neutralization
Method is more accurate, its results are closer to what will actually
B-2.7.3.6
ELA = 0.1059 m ~
(b) Depressurize the enclosure below the ceiling with the door fan
into the -11 Pa to -14 Pa range. Measure the airflow required and the
"pressure created (per B-2. 6.2.5, B-2. 6.2. 6 and B-2. 6.2. 7):
Occur.
Q~ ffi .0512 mS/sec (depressurizing to -12 Pa)
626
/
\
i
NFPA 12A -- A92 TCR
B-2.8 Leakage ControL
should have a flame-spread rating that is compatible with the flame
spread requirements of ~ e enclosure. ' ,
B-2.8.1 Leakage Identification.
B-2.8.1.1 While the enclosure envelope is being pressurized or
depressurized, a smoke pencil or other smoke source should be used
• t o locate and identify leaks.
The smoke source should not be produced by an open flame or any
other source that is a potential source of fire ignition. Chemical
smoke should be usedonly in small quantities and consideration
should be given to the corrosive nature of certain chemical smokes
and their effects on the facility being tested.
13-2.8.1.2 Leakage identification should focus on obvious points of
leakage including wall joints, penetrations of all kinds, FIVAC
ductwork, doors and windows.
]3-2.8.2.2.2 Exposed cellular plastics should not be used for altering
leakage unless considered acceptable by the authority having
jurisctlction.
B-2.8.2.2.3 Cable openings or other penetrations into the enclosure
envelope should be firestopped with material that is compatible with
the fire rating of the barrier.
B-2.9 Test Report.
."
B-2.9.1 Upon completion of a door fan test a written test report shall
be prepared for the authority having jurisdiction and made part of
the permanent record. The test report shall include:
'
.
B-2.8.1.3 Alternate methods for leakage identification are available
and should be considered. One method is the use of a directional
acoustic sensor that can be selectively aimed at different sound
sources. Highly sensitive acoustic sensors are available that can detect
air as it flows through an opening. Openings can be effectively
detected by placin~ an acoustic source on the other side of the
barrier a n d searching for acoustic transmission independent of fan
pressurization or depressurization. Another alternative is to use an
infrared scanning device if temperature differences across the
boundary are sufficient.
(a)
Date, tilne, and location of test
(b)
Names ofwimesses to the test
(c)
Room dimensions and volume
(d)
All data generated during test, including computer printouts
(e) Descriptions of any special techniques utilized by test
technician (i.e., use of optional ceiling neutralization, and temporary
sealing of suspended ceiling)
13-2.8.2 Leakage Alteration.
(f)
In' case of technical judgement, a full explanation and
documentation ofthe judgement
13-2.8.2.1 Procedu~.
B-2.8.2.1.1 Protected areas should he enclosed with wall partitions
which extend from the floor slab to ceiling slab or floor slab to roof.
B-2.8.2.1.2 I f a raised floor continues out of the halon protected area
into adjoining rooms, partitions should be installed under the floor
directly under above-floor border partitions. These partitions should
be caulked top and bottom. If the adjoining rooms share the same
undei'floor air handlers, then the partitions should have dampers
installed the same as required for ductwork.
(g)
Test equipment make, model,'and serial n u m b e r
ih)
Copy of current calibration certificate of test equipment
(i)
Name and affiliation of testing technician, and signature.
Due to time constraints the equations appearing in Appendix B wiU
be revised to a more legible and consistent format d u n n g the Tech
Com Doe part of the revision cycle.
B-2.8.2.1.3 Any holes, cracks, orpenetrations leading into or out of
the protected area should be sealed. This includes ptpe chases and
wire troughs. All walls should be caulked around the reside
perimeter of the room where the walls rest on the floor slab and
whei'e the walls intersect with the ceiling s!ab or roof above,
i
B-2.8.2.1.4 Porous block walls should be sealed slab-to-slab to prevent
gas from passing t h r o u g h t h e block. Multiple coats of paint may be
required.
B-2.8.2.1.5 All doors should have door sweeps or drop seals on the
bottoms, weather stripping around the jambs, latching mechanisms
and door closer hardware. In addition, double doors should have a
weather stripped astragal to prevent leakage between doors and a
coordinator to assure proper sequence of closure.
B-2.8.2.1.6 Windows should have solid weather stripping around all
joints.
B-2.8.2.1.7 All unused and out-of-service ductwork leading into or
from a protected area sl~ould be permanently sealed off (air tight)
with metal plates caulked and screwed in place. Ductwork still in
service with the building air handling unit should have butterfly blade
type dampers installed with neoprene seals. Dampers should be
spring-loaded or motor-operated to provide 100% air shut-off.
Alterations to air conditioning, heaung, ventilating ductwork and
related equipment should be m accordance with NFPA 90A, Standard
for the Installation of Air Conditioning and Ventilating Systems, or
NFPA 90B, Standard for the Installation of Warm Air Heating and Air
Conditioning Systems, as applicable.
B-2.8.2.1.8 All floor drains should have traps and the traps should be
designed to have water or other compatible liquid in them at all
times.
B-2.8.2.2 Materials.
B-2.8.2.2.1 All materials used in altering leaks on enclosure envelope
boundaries, including walls, floors, parutions, finish, acoustical
treatment, raised floors, suspended ceilings and other construction
627
NFPA 12A m A92 TCR
Appendix C Referenced Publications
C-1 The following documents or portions thereof are referenced
within this standard for informational purposes only and thus are not
considered part of the requirements o f this document. The edition
indicated for each reference is the current edition as of the date of
the NFPA issuance of this document.
C-I.I NFPA Publications. Nadonal Fire Protection Association, 1
Batterymarch'Park, P. O. Box 9101, Quincy, MA 02269-9101.
NFPA 10, Standard for PortableFireExtinguishers, 1990 edition'
NFPA 68, Guidefor Venting of Defla~a "~, 1988 edition
NFPA 69, Standard on Explosion tZrevention Systems, 1986 edition
NFPA 71, Standard for the lnstallation,'Maintenance, and Use of
Signaling Systemsfor Central Station Sovice, 1989 edition
NFPA 72B, Standard for Auxiliary ProtectiveSignaling Systems, 1986
edition
NFPA 72C, Standard for Remote Station ProtectiveSignaling Systems, 1986
edition
NFPA 72D, Standa.rdfor Prop~tary Protective'SignalingSystems, 1986
edition
C-1.6 Toxicology References.
1. Paulet, G. "Etude toxicologic[ue et physiopathologique du monobromo.trifluoromethane (CFaBr). Arch. Mal. Prof. Med. Tray.
Secur. SOc. 23:341-348. (Che~ Abstr. 60:738e) (1962).
2. Van Stee, E.W., and K.C. BacL ~Short.term inhalation exposure
to bromotrifluoromethane." Tox. & AppL Phann. 15:164-174 (1969).
3. Clark, D.G. "The toxicity ofbromotrifluoromethane (FE 1301)
in animals and man." Ind. Hyg. Res. Lab. Imperial Chemical
Industries, Alderley Park, Cheshire, Eng. (1970).
4. Trochimowic.z, H.J.; A. Azar;J. B. Ten'ill; and L.S. Mullin: "Blood
Levels of Fluorocarbon Related to Cardiac Serisitization." Part 1I.
Am. Ind. Hyg. Assoc..[.. 35:632-639 (1974).
5. Trochimbwicz, H.J., et al. "The effect of myocardial infarction on
the cardiac sensitization potential of certain halocarbons." J Occup.
Med. 18(1):26-30, 1978.
6. The Hine Laboratories, Inc. "Clinical toxicologic studies on
Freon FE 1301," Report No. 1, San Francisco, Cal. (unpublished)
(1968).
7. Stewart, Richard D.; Newton, Paul E.; Wu, Anthony; Hake, Carl
L.; and Krivanek, Neil D.: =Human Exposure to Ha]on 1301, •
Medical College of Wisconsin, Milwaukee (unpublished) (1978).
NFPA 72E, Standard on Automaiic FireDetectors, 1990 edition
NFPA 72H, Guidefor Testing Proceduresfor Loca~ AuxiliaTy, Remote
Station, and Prolrdetar) ProtectiveSignaling Systems, 1988 edition
NFPA 77, RecomfnendedPractice on Static Electricity, 1988 edition
NFPA 90A, Standardfor the Installation of Air Conditioning and
Ventilating Systems, 1989 Edition
NFPA 90B Standard for the Installation of Warm Air Heating and Air
Conditioning Systems, 1989 Edition.
G-1.7 Flame Extinguishment and Inerting References.
1. Booth, K. Melia, B.J. and Hush IL, A Method for Cnucal
Concentration Measurements for the Flame Extinguishment of
Liquid Surface and Gaseous Diffusion Flames Using a Laboratory
"Cup Burner' Apparatus and Halons 1211 and 1301as
Extinguishants,'June 24, 1976.
2. Ford, C. L., =An Overview of Halon 1301 Systems," in Halogenated
Fire Suppressants, ACS Symposium, Series No 16(1975), pp. 1-63.
3. Dalzell, W. G., "A Determination of the 1~,ammability Envelope of
Four Ternary Fuel-Air-Halon 1301 Systems, Fenwal Inc., ReportDSR624, October 7, 1975.
GI.2 ASTM Publication. American Society for Testing and
Materials, 1916 Race Street, Philadelphia, PA 19103.
ASTM E380-1986, Standard for Metric Practice.
ASTM E779-1981, Standard Test Methodfor DeterminingAir Leakage
Rate byFan Pressuri~.ation.
C-1.3 / ~ ' F Publication. Institute of Electrical and Electronics
E/~sneers, 345 E. 47th St,, New York, NY10017.
I/IEEE C2-1987, National Elea'KcalSafety Code.
4. Coll,Jol~n P., "Inerting Characteristics of Halon 1301 and 1211
with Various Combustibles," Fenwal Inc., Report PSR 661,July 16,
1976.
5. Riley,.]'. F. and Olson, K. R., =Determination of Halon 1301/1211
ThresholdExtinguishment Concentrations using the Cup Burner
Method," Ansul Report AD530-A, July 1, 1976.
6. Bajpai, S. N., "Extinction of Diffusion Flames by Halons," FMRC
Serial No. 22545, Report No. 76-T-59,July 1976.
C-1.4 CSA Publication.. Canadian Standards Association, 178
Rexdale Boulevard, Rexdale, Ontario, Canada Mgw 1R3.
7. Data on file at NFPA.
CAN4-$536.82, Standard for the Inspection and Testing of Existing Fire
Alarm Systems.
CAN/CGSB-149.10-M86, Determination of the Airtightness of Building
- Envelopes by the Fan Depr~su~artion Method.
C-1.8 National Fire Protection Research Foundation References.
Grant, Casey C., Enclosurelntegrlty Procedurefor Halon 1301 Total
• FloodingFire Suppression Systems, 1989.
D1.9 Other References.
C-1.5 Military Specifications. Naval Publications and Forms Center,
5801 Tabor Avenue, Philadelphia, PA 19120.
United Nations Environment Programme: Montreal Protocal on
Substances that Deplete the Ozone Layer-- Final Act 1987, UNEP/
RONA, Room DCZ-0803, United Nations, New York, NY, 10017.
MIL-M-12218C.
628