Codes and Standards for
Ammonia Systems
Stewart Workman, CIRO
Carter Redding, CHMM
Robert Sherry
Condor Earth Technologies, Inc.
Jodi Smith
APCCO
Why Codes and Standards?




Established out of lessons learned by
experience
Learn from the mistakes made by others –
often with catastrophic results (Bhopal,
TOSCO, Chevron, Gibson winery, etc.)
Promotes consistency and reliability
Ensures minimum safety and efficiency
Federal, State, and Local Agencies
and Their Programs

Federal Regulators



EPA – Accidental Release Prevention (ARP) or Risk Management Program
OSHA – Process Safety Management (PSM)
California


EPA – CalARP (RMP) regulated through the CUPA
Cal / OSHA - Various Safety Orders: LOTO, IIPP, Respiratory Protection, Emergency Action
Plan, Emergency Response Plan, Hot Work, HazWOPER, HazCom, Eyewash/ Showers, Heat Illness,
Confined Space, Unfired Pressure Vessels, Mechanical Refrigeration

Emergency Planning



Fire Departments


CUPA – Hazardous Materials Business Plan, Consolidated Contingency Plan
LEPC – Coordination with Local Emergency Response Plans
HazMat Response
Building Departments
Eyewash / Shower ANSI – IIAR II 2008
(cont’d)
Alternatives to hard plumbed units, but do they
provide 15 minutes of flushing time with large
amounts of water as the MSDS recommends?
Alternative to having hard plumbed units in remote
locations.
Codes and Standards Applicable to
Ammonia Refrigeration Systems



ASHRAE 15-2007, 2010
ANSI / IIAR II – 2008
ASTM


IIAR Bulletins









(Per Cal / OSHA)
Systems placed in service before March 13, 1999 shall be constructed according to the 1982 Uniform Mechanical
Code, Chapters 4, 15 and 16 (8 CCR 3248(a)).
Systems placed in service after March 13, 1999 and before January 1, 2008 shall be constructed according to the
1997 Uniform Mechanical Code, Chapters 2 and 11 (8 CCR 3248(b))
Systems placed in service after January 1, 2009 shall be constructed according to 2007 California Mechanical Code (8
CCR 3248(c))
NFPA



109 – IIAR Minimum Safety Criteria for a Safe Ammonia Refrigeration System
110 – Start-up, Inspection and Maintenance of Ammonia Mechanical Refrigeration Systems
111 – Ammonia Machinery Room Ventilation
114 – Identification of Ammonia Refrigeration Piping and System Components
and others
California Fire Code
California Building Code
California Mechanical Code 2010 – Chapter 11 Refrigeration


ASME B31G Manual for Determining the Remaining Strength of Corroded Pipelines
70 - National Electrical Code
497A - Recommended Practice for Classification of Class I Hazardous Locations for Electrical Installations in
Chemical Process Areas
8 CCR Division of Industrial Resources


Section 458-Unfired Pressure Vessel Safety Orders
Section 3248 – Mechanical Refrigeration
Codes and Standards Applicable to Ammonia
Refrigeration Systems (condensed)










ASHRAE 15-2007, 2010
ANSI / IIAR II – 2008
ASTM B31.5
IIAR Bulletins
California Fire Code
California Building Code
California Mechanical Code 2010 – Chapter 11 Refrigeration
(Per Cal / OSHA)
70 - National Electrical Code
497A - Recommended Practice for Classification of Class I
Hazardous Locations for Electrical Installations in Chemical
Process Areas
8 CCR Division of Industrial Resources
Is this “YOUR” system?
What codes and standards were used here? It may work, but….
Are the same type of shortcuts done in our systems?
How It All Fits Together




OSHA and Cal / OSHA do not write specific standards for
ammonia refrigeration, but instead rely on manufacturers'
recommendations and codes and standards written by industry
leaders such as ASHRAE, ANSI, and IIAR.
Recognized and Generally Accepted Good Engineering
Practice (RAGAGEP).
Federal EPA and Cal EPA write the requirements for the ARP
programs and enforce their implementation through
themselves (Region 9 EPA) and the local CUPA.
General Duty Clause – A fallback when specific regulations
do not specify compliance requirements. This is not enforced
by the CUPA but is by Region 9 EPA.
How It All Fits Together (cont’d)

California Mechanical Code in 2010 Revision:
1102.0 General
“Except as modified by this code, refrigeration
systems shall comply with ASHRAE 15. In addition,
ammonia refrigeration systems shall comply with
IIAR II.”
Eyewash Shower ANSI – IIAR II 2008

13.3.1.4 – An eyewash and body shower unit shall be located external to
the machinery room and readily accessible via an exit.

NOTE: It is recommended that additional such units be located accessibly
within the engine room such that no unit is further than 50 ft [15m] from
any point in the room. (OSHA additionally calls for unit access to be free
from obstructions and on the same level).
 Recommended means that a unit shall be placed in
the engine room to avoid citation.
 8 CCR 5162 requires that a unit be placed within
10 seconds of an exposure (injured person).
Cal/OSHA figures between 4.5 and 5. 5 feet per
second. ANSI 358.1-1981 requires that an
eyewash should be within 3 meters (10 feet) of a
strong acid or caustic.
ASHRAE 15-2004, 2007, 2010
Safety Standard for Refrigeration
Systems


9.7.2.1 Vessels of <3 cu. ft.
internal gross volume shall
have one or more pressure
relief valves or fusible plugs.
9.7.2.2 Vessels ≥3 cu. ft. &
<10 cu. ft. internal gross
volume shall have one or
more pressure relief valves.
Fusible plugs will not be
used.
Potential Problems with Emergency
Pressure Control Systems



An “Emergency Pressure Control System” is
an automated system.
According to the 1982 UMC “shall be
equipped with means for manual discharge of
the refrigerant to the atmosphere.
Bottom Line; T8 3248(a) does not allow the
use of a Emergency Pressure Control System.
2010 California Mechanical Code
Diffusion Tanks


1120.0 New requirement – Ammonia shall
discharge into a tank of water that shall be used
for no purpose except ammonia absorption. At
least one (1) gallon (3.785 l) of fresh water shall
be provided for each pound (454 g) of ammonia
that will be released in one (1) hour from the
largest relief device connected to the discharge
pipe.
Old requirement was one (1) gallon of water for
each pound of ammonia in the system.
ANSI – IIAR II 2008

5.4.2.1 – Anti-seize and /or lubricating compounds that contain copper
shall not be used in contact with ammonia piping.

11.2.5.ii – The capacity of any dual relief assembly whose manifold (3way) valve is set to a position other than fully seated (one side open and
one side closed) shall be considered zero.
Pressure Relief
ANSI – IIAR II 2008


11.3.3 – The discharge
piping from pressure relief
devices shall comply with the
materials requirements of
10.2.1. (same as for rest of
system). EXCEPTION:
Relief Piping is permitted to
be galvanized or ungalvanized ASTM A120,
A53/A120, or A53 Type F.
Improper
Materials of
Construction
11.3.6.2 – Discharge piping from pressure relief devices piped to
atmosphere shall have provision for draining moisture from the piping.
What’s wrong with this picture?
Location is over a walkway
at 8’ elevation.
Pipe material?
Drilled weep hole
How about these?
Earthquake bracing?
Corrosion?
Materials of Construction?
ANSI – IIAR II 2008 (cont’d)

New Trend APPENDIX K – informative – Emergency
Pressure Control Systems.
Provides a method to internally mitigate an overpressure event in a
refrigeration system that is independent of other required safety features
and functions prior to operation of a pressure relief device. Essentially an
internal relief system that uses pressure sensors and a solenoid valve that
opens a path from the discharge side to the suction side of the system that
operates prior to a relief valve lifting.

CMC 1122.0 Emergency Pressure Control Systems
When required by the fire code, an emergency pressure control system
shall be installed in accordance with applicable fire code requirements.

CFC 606.10 Emergency Pressure Control Systems
Required in Refrigeration systems containing more than 6.6 pounds of
flammable, toxic or highly toxic refrigerant or ammonia.
Appendix K – Emergency Pressure
ANSI – IIAR II 2008
IIAR Bulletin 111 - Ammonia Machinery
Room Ventilation and 2010 CMC §1108



1108.2 – Dedicated mechanical exhaust
1108.2.1 – Continuous ventilation of room at
0.05 inch water gauge negative pressure
relative to adjacent places as calculated by
Q=2610Ae√∆p
1108.2.3 – Limit the temperature rise within
the refrigeration machinery room to a
maximum of 104 F (40 C) as calculated by
Q=∑q/1.08∆T
California Mechanical Code
1107.7 Special Requirements

Open flames or
devices having an
exposed surface
exceeding 800 F are
prohibited in
refrigeration
machinery rooms.
Corrosion – How Deep is too Deep?

ASTM B 31G – Manual for Determining the
Remaining Strength of Corroded Pipelines.
Developed for Oil and Gas
 Can be applied to refrigeration piping
 Example – 0.04
in depth flaw
must be less
than 0.6” long
(wall thickness
.109”)

Ventilation
Ventilation, Alarm, and Shutdown Levels
1107.4 CMC Machinery room shall have
approved detectors in areas most likely to
accumulate vapors. Trigger audible and
visual alarms.
Level not greater than the lesser of:
.5 x IDLH = .5 x 300 ppm or 150 ppm or
PEL = 25 ppm or
25% of LFL = 25% of 15% or 37,500 ppm
1108.2.3 CMC Limit machinery room
temperature rise to maximum.
104 F maximum room temperature
1108.4 CMC Automatic ventilation purge
Maintain level less than PEL: 25 ppm
of machinery room (intermittent as required).
Previously required continuous ventilation.
1108.5 CMC Automatic ventilation purge
of machinery room (emergency purge).
1000 ppm
1109.4 CMC Manual “Break Glass”
switches outside of machinery room and
automatic shutdown of all machinery room
electrical.
25% of Lower Flammability Limit (LFL)
25% of LFL = 25% of 15% or 37,500 ppm
IIAR Bulletin 111 - Ammonia Machinery
Room Ventilation and 2010 CMC 1108
(cont’d)

1108.2.4 Provide emergency purge of escaping refrigerant as
calculated by Q=100√G
Where:
q= Btu/h of all heat producing equipment
Q= air flow rate, cubic feet per minute (cfm)
∆p= pressure difference, inches of water gauge
Ae= equivalent leakage area, square feet (see the building code)
Agf = gross floor area, square feet
∆T= temperature difference between machinery room and supply
air ( F)
G= refrigerant mass in largest system, lbs
IIAR Bulletin 111 - Ammonia Machinery
Room Ventilation and
2010 California Mechanical Code 1108
(cont’d)

1108.5 Emergency Control of the
Ventilation System
1.
2.
Clearly Identified “Break Glass,” “on” only control on
outside of each machinery room door.
For ammonia, system shall automatically respond to
detector system at no more than 1,000 ppm. Manual
reset only on control system.
2010 California Mechanical Code 1109
(cont’d)
1109.4 Emergency Control

1.
Clearly identified “Break Glass” type switch for “off”
only control of electrically energized equipment and
devices inside the machinery room shall be provided
immediately adjacent to and outside of each
refrigeration machinery room exit. Automatic
shutdown control activation is required when the
concentration of refrigerant vapor exceeds 25% of the
Lower Flammability Limit (LFL).
Ventilation, Alarm, and Shutdown Levels
1107.4 CMC Machinery room shall have
approved detectors in areas most likely to
accumulate vapors. Trigger audible and
visual alarms.
Level not greater than the lesser of:
.5 x IDLH = .5 x 300 ppm or 150 ppm or
PEL = 25 ppm or
25% of LFL = 25% of 15% or 37,500 ppm
1108.2.3 CMC Limit machinery room
temperature rise to maximum.
104 F maximum room temperature
1108.4 CMC Automatic ventilation purge
Maintain level less than PEL: 25 ppm
of machinery room (intermittent as required).
Previously required continuous ventilation.
1108.5 CMC Automatic ventilation purge
of machinery room (emergency purge).
1000 ppm
1109.4 CMC Manual “Break Glass”
switches outside of machinery room and
automatic shutdown of all machinery room
electrical.
25% of Lower Flammability Limit (LFL)
25% of LFL = 25% of 15% or 37,500 ppm
New! IIAR PSM and RMP
Guidelines 2012 Edition

NEC electrical classification of areas outside
of compressor rooms may be required.
Example: Refrigerated rooms with control groups
which may leak ammonia.
 Exceptions

Rooms that have adequate ventilation and where
combustibles are contained in well maintained piping
and
 Rooms that have no ventilation but do not have flanges,
valves, fittings, etc. that may be prone to leaks

PSI Draft IIAR 2 Guidelines (normative)

8 Electrical Classification


The areas containing refrigeration piping and equipment that are not
located in machinery rooms may need to be classified for NEC
purposes.
Experience has shown, however, that the release of ignitable mixtures
from some operations and apparatus is so infrequent that area
classification is not necessary. For example, according to NEPA-497A
it is not usually necessary to classify the following locations where
combustible materials are processed, stored, or handled:


(I) Locations that are adequately ventilated, where combustible materials
are contained within suitable, well maintained, closed piping systems; and,
(2) Locations that are not adequately ventilated but where piping systems
are without valves, fittings, flanges, and similar accessories that may be
prone to leaks.
How are different codes and standards
that conflict with each other interpreted?

Laws & Regulations

Chaptered into Code

Regulations developed by agencies




Performance specifications
RAGAGEP from authoritative groups
Regulations administered by different agencies
RAGAGEP (Recognized and Generally Accepted Good
Engineering Practices)

General Duty Clause
What happens if we ignore the
codes?

Normal Org Chart
(before accident)
Responsible
Person
You are here
Required Work

Revised Org Chart
(after accident)
Required Work
Questions
Condor Earth Technologies, Inc.
Office Locations:
Merced
Roseville
Sonora
Stockton
(800) 800-0490