PETROJET THE PETROLIUM PROJECTS & TECHNICAL CONSULTATIONS COMPANY
Plastic Pipes
Plastic pipes for Piping Engineering issues
Mohammed Kamal Kamal Gaber
27/12/2016
Paper is introducing a research on thermoplastic pipes uses and design, as plastic pipes have been used widely
in many oil, water, and gas process plants and pipelines for many issues instead of metal pipes as their lower
cost, easier installation, and lighter weight than other metallic pipes.
M.Kamall
ne Design
Pipiing and Pipelin
Engineerr
A
MNI MBA
Subjecct.
Plaastic pipes for piping
p
Engineerring issues
ment.
Docum
Reesearch
Date.
277/12/2016
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1 of 47
Table of Contentts
INTRODUC
CTION
4
1.1 Backgro
ound
4
1.2 Principle
e Materials
5
2.
SCOPE
5
3.
LE PRODUCT
TS
AVAILABL
5
4.
PRINCIPLE
E USES
7
4.1. Rehabiilitation Tech
hnology
8
ADVANTAG
GES AND LIIMITATIONS
S
9
5.1. Advanttages
9
5.2. Limitatiions
9
5.3. Require
ements for successful de
esign
10
THERMOPLASTIC PIP
PING MATER
RIALS
11
ers Definition
n
6.1. Polyme
11
1.
5.
6.
6.1.1. Chemicall geometry
6.2. Plasticss Compositio
on materials
7.
11
12
6.2.1. Plastics Additives
A
12
ne materials
6.2.2. Crystallin
13
6.2.3. Thermoplastics Materrials
13
6.2.4. Cell classsification
14
LY USED TH
HERMOPLAS
STIC PIPES
COMMONL
14
7.1. Polyvin
nyl Chloride ((PVC) Pipe
14
7.2. Chlorin
nated Polyvin
nyl Chloride (CPVC)
(
Pipe
e
17
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7.3. Polypro
opylene (PP)) Pipe
18
8
7.4. Acrylon
nitrile-Butadie
ene-Styrene (ABS) Pipe
18
8
7.5. Polyeth
hylene (PE) Pipe
P
19
9
8.
DESIGN AN
ND INSTALL
LATION
21
9.
COMMON DESIGN
D
AN
ND INSTALLA
ATION CON
NSIDERATIO
ONS
23
3
9.1. Internal Hydraulic P
Pressure
23
3
essure
9.1. 1.Surge Pre
10.
11.
12.
13.
24
4
9.2. Resista
ance to Vacu
uum and Exte
ernal Pressu
ure
27
7
9.3. Temperature Effectts
28
8
CONSIDER
RATIONS FO
OR ABOVEG
GROUND US
SES
29
9
10.1. Suppo
orts and Ancchors
29
9
10.2. Suppo
ort Spacing
30
0
10.3. Expan
nsion-Contra
action
31
CONSIDER
RATIONS FO
OR BELOWG
GROUND US
SES
3
33
11.1. Pipe-S
Soil System Parameters
34
4
11.1.1. The hoo
op stiffness parameter
p
35
5
11.1.2. The bed
dding stiffnes
ss parameterr
35
5
ANSATION FITTING
F
PE / METAL PIPE TRA
35
5
12.1. Example, Vendor Print for PE / Metal Transition Fitting
36
6
LINED PIPIN
NG FOR COR
RROSION RESISTANCE
E
PLASTIC-L
39
9
13.1 History
y
39
9
13.2. METH
HODS OF MA
ANUFACTURE
39
9
13.2
2.1. Liner Ma
anufacturing Processes for
f PTFE Lin
ners
13.3. Liner Materials
39
9
40
0
M.Kamall
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13.3.1. Liner Ty
ypes
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41
ed Cost Com
mparisons
13.4 Installe
41
14.
INSTALLAT
TION
3
43
15.
SOURCES OF ADDITIO
ONAL INFORMATION
43
3
ew Developm
ments
15.1. On Ne
43
3
15.2. Public
cations Relatted to Standa
ards
44
4
15.3. Assoc
ciations
44
4
15.4. Codes
s
44
4
REFERENC
CES
46
6
16.
M.Kamall
ne Design
Pipiing and Pipelin
Engineerr
A
MNI MBA
1.
Subjecct.
Plaastic pipes for piping
p
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INTRODUC
CTION
Plastics pip
ping are mad
de from either of two ba
asic groups of synthetic materials, tthermoplastic
c and thermosetting.
Thermoplas
stics can be
e softened and
a
reshape
ed repeatedlyy by the ap
pplication of heat. In co
ontrast therm
mosetting
materials are
a irreversib
bly set, or cured,
c
or hardened into a permanen
nt shape du
uring factory manufacturre. Once
hardened in
nto their fina
al shape, the
ermosetting products
p
can
nnot be softe
ened and the
erefore may not be resh
haped by
heating.
stic materialss include min
nimal reinforrcements, wh
hereas therm
mosetting ressins are almo
ost always combined
Thermoplas
with reinforrcements (su
uch as glass
s fibers) and sometimes fillers (such
h as sand) to
o produce structurally in
ntegrated
composite constructions
c
s.
1.1. Backgrround
The first the
ermoplastic tubes
t
were made
m
in Gerrmany during
g the 1930s from a PVC copolymer. Thermoplas
stics pipe
was first manufactured commerciallly in the Un
nited States in 1940 from
m cellulose a
acetate buty
yrate (CAB) and was
used by The Southern California Ga
as Company
y for distributting natural gas.
g
Volume
e production commenced
d in 1948
when PE pipe
p
was firs
st offered forr non-code-rregulated wa
ater service applicationss. ABS and PVC pipe were
w
first
commerciallly made in the United States in 1949
1
and 1950, respec
ctively. Durin
ng the 1940
0s and 1950
0s many
fundamenta
al advancess were intro
oduced in polymer
p
che
emistry, matterials formu
ulation, and product fa
abrication
technology,, which laid the foundattion for the thermoplasti
t
cs pipe indu
ustry. Improvvements in these
t
areas are still
continuing. However, th
he start of th
he evolution
n of thermop
plastics piping as engine
eering materials is considered to
n place in 19
950 when an
a American Society forr Testing and Materials (ASTM) gro
oup for plasttics pipe
have taken
standardiza
ation was orrganized. So
oon thereafte
er the first ASTM
A
stand
dards coverin
ng materials
s, test metho
ods, and
piping prod
ducts began to be issue
ed. At prese
ent over 180
0 ASTM sta
andards defiine plastic piping,
p
plastiic piping
materials, te
est methods, and recommended prac
ctices for join
ning and installation. Num
merous plastics piping sttandards
have also been
b
issued b
by other orga
anizations.
1.2. Princip
ple Materials
s
Thermoplas
stics accoun
nt for the lio
on’s share of plastics used for piiping. During
g 1989,overr 95 percen
nt of the
approximate
ely 7.5 billio
on pounds (3.75 million
n metric ton
ns)of plastics
s that went into pipe, conduit, and
d fittings
consisted of
o thermoplas
stics.1Polyviinyl chloride (PVC) acco
ounted for ab
bout three-qu
uarters of all thermoplas
stic pipe.
The second
d most widelyy used therm
moplastic is polyethylene
p
e (PE), accou
unting for ab
bout a 15 perrcent share, followed
by acrylonittrile-butadien
ne-styrene (A
ABS), represe
enting aboutt a 4 percent share. The balance about 6 percent consists
of special-p
purpose ma
aterials, such
h as chlorin
nated polyvin
nyl chloride (CPVC), crross link ed
dpolyethylene
e (PEX),
polybutylene (PB), polyypropylene (P
PP), and varrious fluorina
ated polymerrs, Principlelyy polyvinylide
ene fluoride (PVDF).
M.Kamall
ne Design
Pipiing and Pipelin
Engineerr
A
MNI MBA
Subjecct.
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In 1955, tottal U.S. Ship
pments of the
ermoplastic pipe
p
were les
ss than 40 million
m
pound
ds (18,000 metric
m
tons). By
B 1998,
the rate of shipments
s
ha
ad increased
d almost 200 fold, and it is
s still growing.
More footag
ge of thermo
oplastic pipe is now bein
ng installed tthan that of all
a other type
es of piping materials co
ombined.
However, th
he total dolla
ar value of in
nstalled therm
moplastic pip
pe is second
d to and onlyy about one-q
quarter of th
hat of the
leading matterial, steel.3
3 this is beca
ause the Prin
nciple use of thermoplastics piping is in the smalle
er sizes. But the very
successful track record in these siz
zes has been leading to increasing acceptance
a
and use of the
t larger dia
ameters,
which curre
ently comprisse the fastestt growing segment. As off this writing, thermoplasstic pipe is av
vailable throu
ugh NPS
60 (DN1500
0) for pressure uses and NPS 108 (D
DN 2700) for sewer and drain
d
applicattions.
2.
SCOPE
he Principle properties and
a
uses of thermoplas
stics piping, discusses its advantages and
This Paperr reviews th
limitations, and presen
nts general and basic information on materialls, propertie
es, standardization, design, and
installation. This informa
ation is inten
nded to guide
e the reader in evaluating
g the applica
ability of therrmoplastics piping
p
for
an intended
d application; in choosing
g the approp
priate material and produ
uct; and in itts proper design and ins
stallation.
References
s are provided for more detailed inform
mation and fo
or further guidance on th
hese and rela
ated subjects
s.
3.
AVAILABL
LE PRODUCT
TS
Plastics pipe and fittings
s are availab
ble in a vast array
a
of mate
erials, diame
eters, wall thiicknesses, and designs. For nonpplications special wall constructions
c
s are offered
d—such as double
d
wall, ribbed, and foamed core
e—which
pressure ap
are designe
ed to more ec
conomically achieve a de
esired longitu
udinal and diiametrical pip
pe stiffness.
Most of the
ese productss are covere
ed by nation
nal standards. Table 1.1
1, which listss common standards
s
th
hat cover
Principle co
ommercial products, also
o identifies each producct’s primary application and gives th
he range of nominal
sizes coverred by the sttandard. As the updating
g of existing
g and the writing of new product standards is a dynamic
ongoing pro
ocess, the re
eader is advis
sed to contact standardss-issuing orga
anizations fo
or the latest status.
s
The American
A
Society for Testing and
d Materials (A
ASTM),*for example,
e
eac
ch year upda
ates a volum
me of it's ‘‘An
nnual Book of
o ASTM
udes all of itts current sttandards covering plastiics piping. The
T
Plastics Pipe Institu
ute (PPI)
Standards’ ‘which inclu
publishes a periodically
y updated re
eport, PPI TR
R-5, which includes a co
omprehensivve listing of North Ameriican and
Internationa
al Standardss Organizatio
on (ISO) stan
ndards on th
hermoplastics piping. There are also
o many comm
mercially
available piping appurte
enances, suc
ch as identifiied in Table D3.1, that are
a fabricated
d from plastics but which
h are not
covered by any national standard. In
n addition, some pipe an
nd fitting man
nufacturers a
and their disttributors can customfabricate co
omponents th
hat may or may
m not be shown
s
in pro
oduct catalog
gs. These sp
pecials includ
de manholes
s for both
infrastructurre and indus
strial applicattions. Fabric
cated fittings intended forr pressure se
ervice are offten reinforce
ed by an
overwrap with
w a glass-fiber thermosetting resin composite.
c
M.Kamall
ne Design
Pipiing and Pipelin
Engineerr
A
MNI MBA
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Table 1.1
aterial
Piping ma
and prod
duct
standard
d
Subject product,
p
or
abbrevia
ated title of
standard
d
nal
Nomin
sizes
range((in)
Principle
e
applicattions
ABS,PP and
d PVC
ASTM D331
11
D
DWV
fittings patterns
1¹⁄₄– 8
Drain, waste vent
4–15
Sewer drain
1¹⁄₄– 1¹⁄₂
Drain, waste vent
2–16
asing
Water-well ca
Drain, waste vent
ABS and PV
VC
ASTM D268
80
A
ABS
and PVC sewer pipe off composite wall
9
ASTM F409
construc
ction
ble and replac
ceable tube an
nd
Accessib
fittings
ASTM F480
0
ASTM F149
99
Thermop
plastic water well
w casing
Coextrud
ded, composite DWV pipe
CSAB181.5
Coextrud
ded ABS/PVC
CDWV pipe
1¹⁄₄–
–8
1¹⁄₄–
–6
Drain, waste vent
CPVC
ABS,PVC&C
ASTM F148
88
Coextru
uded composiite pipe
2–1
12
Drain, waste & vent;
sewer
ABS
ASTM D1527
ABS Pipe, Schedules 40
0and80
ASTM D2
2282
ABS Pipe, dimension rattio series
¹⁄₈–12
Coldwater; in
ndustrial
ASTM D2
2468
ABS Socke
et fittings, Sch
hedule 40
¹⁄₈–8
8
ndustrial
Coldwater; in
ASTM D2
2661
ABSDWV pipe and fittings
ASTM D2
2750
y conduit and fittings
f
ABS Utility
1–6
Electrical du
uct
ASTM D2
2751
ABS Sewe
er pipe and fittings
3–12
Sewer drain
ASTM F6
628
ABS Foam
m core DWV
1¹⁄₄–
–6
Drain, waste vent
CSAB181.1
ABSDWV pipe and fittings
1¹⁄₄–
–6
Drain, waste vent
¹⁄₈–1
12
1¹⁄₄–
–6
ndustrial
Coldwater; in
Drain, waste & vent
PA
ASTM F1
1733
CSAB13
37.12
on fittings for polyamide pip
pe
Butt heat fusio
Polyamide piiping systems for gas servicce
1/2 – 48
1/2 – 8
Gas distrribution
Gas distribu
ution
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Table 1.1
Piping matterial and
product sta
andard
Subject product,
ated title of standard
s
or abbrevia
minal
Nom
sizes
s range (in)
ple
Princip
applica
ations
ASTM D210
04
PE pipe, Sc
chedule 40, ID
I based
1⁄2–6
Cold water,
w
industriial
ASTM D223
39
PE pipe, dim
mension ratio
o series, ID based
b
1⁄2–6
Cold water;
w
industriial
ASTM D244
47 PE
Pipe, Sched
dules 40 & 80
1/2–12
Cold water;
w
industriial
ASTM D260
09
Plastic inse
erts fittings fo
or PE pipe
1/2–6
Cold water
w
ASTM D268
83
PE fittings, socket fusion type
1/2 - 4
Cold water;
w
natural gas;
ASTM D273
37 PE
tubing
1/2 –2
Cold water
w
ASTM D303
35
PE pipe, dim
mension ratio
o series
1/2 –6
Cold water;
w
industriial
ASTM D326
61
PE fittings, butt fusion ty
ype
1/2 –48
Cold water;
w
natural
PE
4.
PRINCIPLE
E USES
Thermoplas
stics piping are
a routinely used for much common pressure and no pressurre application
ns. Approxim
mately 80
percent of the
t
newly in
nstalled main
ns and 90 pe
ercent of the
e services fo
or gas distrib
bution are made
m
of PE. Over 90
percent of rural water distribution mains
m
and over
o
40 perccent of municipal mains are made of
o PVC. Mos
st of the
smaller-diam
meter piping
g installed for agricultura
al and turf irrrigation is made primarilyy from PE and
a PVC. CP
PVC and
PEX piping are increasingly used fo
or hot/cold wa
ater distributiing piping for residential and other co
onstruction. In oil and
gas producttion, significa
ant quantities
s of PE pipe
e are used to
o convey water and well g
gases. Therm
moplastics piping are
also freque
ently used fo
or commercia
al and indus
strial applicattions such as
a for conveyying chilled and process
s waters,
aqueous so
olutions of corrosive
c
che
emicals, slurries, foods, and substa
ances that must
m
remain uncontamin
nated by
metallic ions.
More than half the tonnage of all thermoplasti
c pipes goe
t
es into no prressure usess. Over 85 percent
p
of th
he newly
installed un
nderground b
building sewer connectio
ons are made of PVC. PVC
P
also acccounts for a similar share of the
sewer colle
ection mains in sizes NP
PS 4 through
h 18 (DN 10
00 through 450).
4
About 80 percent of new sing
gle-family
dwellings uttilize either PVC
P
or ABS drain, waste
e, and vent (DWV) piping
g. Most drain
nage systems
s, including those
t
for
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building fou
undations, leaching fields
s, agriculture
e, and road cconstruction now consistt of thermopllastics piping
g, mostly
PE and PVC
C. And both PVC and PE
E are increas
singly used fo
or larger diam
meter sewers
s, drains and
d culverts. One of the
faster grow
wing applicatiions is the use
u of PE and PVC pipe
es of profile
e wall constructions for drainage,
d
pa
articularly
alongside and
a
under ro
oadways (se
ee Fig. 1.1). Another is the rehabilittation of olde
er sewers, drains,
d
and pressure
pipelines by
y the insertio
on of new PE
E or PVC pipe
es.
Fig. 1.1
4.1. Rehabilitation Tec
chnology
In one reha
abilitation tec
chnology a PE
P or PVC pipe
p
is deform
med when manufactured
m
d into a ‘‘U’’ shape
s
appro
oximately
one-half the
e diameter of
o the host pipe. At the in
nstallation sitte, the ‘‘U’’ deformed pipe is pulled th
hrough the damaged
d
host pipe and then reformed by a combination
c
o heat and pressure
of
p
to tightly
t
fit the shape of the host pipe (see
(
Fig.
1.2)
Fig. 1.2
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ADVANTAG
GES AND LIIMITATIONS
S
A number of
o important performance
e advantages
s have spark
ked the wide spread adoption of therrmoplastics piping
p
for
so many pre
essures and no pressure
e uses.
5.1. Advantage
es

The most universally recognized
r
a
advantage
is the piping
g’s virtual frreedom from
m attack by ambient wa
ater and
T
cs piping are
a not subject to surfa
ace attacks in any wayy comparable to the ru
usting or
moisture. Thermoplasti

environmen
ntal corrosion
n of metals.
Thermoplas
stics, being nonconductors, are imm
mune to the
e electroche
emical-based
d corrosion process induced by
electrolytes such as acid
ds, bases, and salts. In addition,
a
plas
stics pipe ma
aterials are n
not vulnerable
e to biologica
al attack.
ermoplastics are not sub
bject to corro
osion in most environme
ents in both
h abovegroun
nd and unde
erground
In sum, the
service. Th
his has resulted in negligible costs for mainten
nance and external
e
prottection such as painting
g, plastic

coating, galvanizing, ele
ectroplating, wrapping, an
nd cathodic protection.
p
Another Prrinciple adva
antage offere
ed by therm
moplastics is
s their lowerr specific grravity, which
h results in ease of
handling, sttorage, and installation, as well as in lower tra
ansportation costs. The smooth pipe
e surfaces yield
y
low
friction facto
ors and very low tendenc
cy to fouling. They also offer
o
very goo
od abrasion rresistance, even
e
when co
onveying

slurries thatt can rapidly abrade hard
der materials.
High deform
mation capacity without fracture—orr strain abilitty (Janson)—
—is another important performance
p
feature,
particularly for undergro
ound service
e. In respons
se to earth lo
oading, burie
ed flexible pip
pes deform (deflect)
(
and
d thereby
activate add
ditional and substantial
s
support
s
from the surrounding soil. Th
his capability to activate additional
a
su
upport by
deformation
n results in a pipe-soil structure tha
at is capablle of supporrting earth ffills and surfface live loa
ads of a

magnitude that
t
could fra
acture strong
ger but less stainable
s
materials.
Thermoplas
stics piping, particularly
p
in
n the sizes under
u
around
d NPS 18 (DN
N 450), can be competittive in cost to piping
of other ma
aterials. In the
t
larger sizes, thermo
oplastic swilll oftentimes overcomes a first-cost disadvantag
ge when
consideratio
on is given to
o their lower operating an
nd maintenan
nce costs an
nd longer life..
5.2. Limitations
s


The Princip
ple limitationss of thermoplastics arise from their re
elatively low strength and
d stiffness and greater sensitivity
of mechanic
cal propertiess to tempera
ature.
As a result, their prima
ary use is fo
or gravity and lower-presssure applica
ations at ne
ear ambient temperatures. Some
plastics qua
alify for hot water servic
ce, and there
e are some specialty ma
aterials that can be use
ed to close to
t 300_F
(149_C).
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Notwithstan
nding these rrestrictions, thermoplastic
t
cs piping sattisfy the perfformance req
quirements fo
ora very broa
ad range
of applicatio
ons.
5.3. Requirrements for successful design
Successful design with thermoplastiics requires recognition o
of their viscoelastic naturre. These ma
aterials do no
ot exhibit
the relative
ely simple sstress/strain relationship that is cha
aracteristic of
o metals. D
Duration of loading, as well as
temperature
e and enviro
onment, can have a profo
ound effect o
on their stres
ss-strain response, ruptu
ure strength, ultimate
strain capa
acity, and other enginee
ering properties. The extent
e
to wh
hich duration
n of loading
g, temperatu
ure, and
environmen
nt influence ultimate mechanical pro
operties varie
es not only from one class of therm
moplastic ma
aterial to
another (for example, between PV
VC and PE) but can als
so significan
ntly differ within the sam
me generic material,
depending on the spec
cific nature of
o the polym
mer (e.g., mo
olecular weig
ght, molecula
ar weight distribution, degree of
branching, and extent o
of copolyme
erization with
h other mono
omers), the type and qu
uantity of po
olymer additives and
modifiers, and
a
the proc
cessing cond
ditions. Thes
se factors m
must be recognized when
n characteriz
zing the eng
gineering
properties of
o thermopla
astic piping, particularly
p
w
when
definin
ng allowable stress, strain, and uppe
er temperature limits;
and it goes without say
ying that for effective des
sign and installation, the
ey must be g
given conside
eration by th
he piping
ns creator, designer,
d
and
d user.
specification
Compared to
t traditional piping mate
erials, thermo
oplastics hav
ve high coeffficients of the
ermal expans
sion and con
ntraction.
For examplle, the therm
mal expansio
on rate can be
b from 6 to
o 10 times greater than that
t
of meta
al pipe. This must be
recognized both in desiign and insta
allation, particularly for a
aboveground applicationss where resu
ultant piping reaction
may require
e frequent us
se of expansion loops or pipe supportts. For above
eground piping more atte
ention may also
a
need
to be given
n to proper pipe
p
restrain
nt because the
t
low mas
ss of thermo
oplastics provides less in
nertia agains
st piping
movements
s that may be induced
d by sudde
en changes in the fluid flow velo
ocity. Additio
onally, abov
veground
thermoplasttics should b
be positioned
d or protected
d against pos
ssible accide
ental mechan
nical damage
e.
Since therm
moplastics a
are combustiible, their us
se in certain
n locations may
m
be limitted by fire safety
s
conce
erns and
regulations.. Constructio
on and building codes address
a
thesse concerns through varrious requirements, inclu
uding the
placing of thermoplasticcs piping ins
side suitable fire-resistan
nt walls and chases and the use of fire
f stops wh
hen pipe
t
such
h structures.
penetrates through
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THERMOPLASTIC PIP
PING MATER
RIALS
6.1. Polyme
ers Definitio
on
The term po
olymer (from
m the Greek poly,
p
meanin
ng ‘‘many,’’ and
a mer mea
aning ‘‘unit’’) is used to denote the long-chain
or network structure of macromolec
cules that arre produced either natura
ally or that a
are made by
y man. The latter are
a synthetic polymers. Po
olymers whic
ch are the ba
ase material for plastics a
are oftentime
es termed res
sins.
referred to as
Polymers used for engineering appllications con
nsist of relativ
vely long mo
olecules in orrder to yield satisfactory levels of
longer-term
m strength, du
uctility, and to
oughness.
Molecule siize is denote
ed by molec
cular weight,, which is th
he sum of th
he atomic ma
asses of all the elements in the
molecule. Since
S
all the
e molecules in a polyme
er are not off the same size,
s
the deg
gree of polym
merization is
s usually
expressed by
b the polym
mer’s average
e molecular weight. The nature of the distribution
n of molecula
ar sizes also
o bears a
significant influence on a number off physical an
nd mechanica
al properties
s. Thermopla
astics used fo
or piping app
plications
tend to be of relativelyy high molec
cular weight (generally over
o
100,000
0) and of rellatively narro
ow molecula
ar weight
ar weight can
nnot be so la
arge as to re
esult in a me
elt viscosity so high as to
t hinder
distribution.. However, the molecula
proper fabrication of the
e end produc
ct. Another molecular
m
strructural para
ameter is the
e length and frequency of
o shorter
c
that o
occasionally branch out from the ma
ain polymer chain. Thesse branches help determ
mine how
molecular chains
closely the polymer mo
olecules can
n lie next to each other, which has an influence
e on the pollymer’s phys
sical and
a frequenc
cy of polyme
er branches may be con
ntrolled by co
onditions of chemical
c
mechanical properties. The length and
atalysts use
ed, and by the copolym
merization with
w
other th
han the Principle mono
omer. For example,
e
reaction, ca
polyethylene pipe polym
mers are in fa
act copolyme
ers of ethylene with sma
all amounts o
of other olefin
n monomers such as
propylene, butene, pen
ntene, and hexene.
h
Altho
ough the am
mount of oth
her monomers used is lo
ow, and the
ereby the
polymer stilll falls under the classific
cation of poly
yethylene, it is enough to
o modify the
e polymer’s molecular
m
strructure—
Principlely the
t number of short bran
nches along the linear m
molecular chains—and th
hereby exertt significant influence
on engineering propertie
es. Many commercial po
olymers, inclu
uding polypro
opylene (PP)) and polybu
utylene (PB), are also
olymers.
partial copo
6.1.1 Chemicall geometry
emical geom
metry, some
etimes referrred to as polymer arch
hitecture, alsso helps de
etermine the relative
Che
phy
ysical arrangement of mo
olecules to on
ne another a
and, thereby, the polymerr’s physical properties.
p
Generally,
the long molecu
ules in polym
mers tend to align
a
themse
elves near ea
ach other in a random sym
mmetry analogous to
spa
aghetti in a bowl. This random arra
angement is referred to as the amo
orphous state. The prox
ximity of
poly
ymer molecu
ules to one another and
d their phys
sical entanglement givess rise to me
echanical forrces that
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greatly accountt for a polym
mer’s mecha
anical prope
erties. PVC and ABS arre polymers that are es
ssentially
amorphous matterials.
6.2. Plastic
cs Composittion materia
als
Plastics are
e compound
ds of resinss and additivves. As pre
eviously expllained, plasttics are diviided into tw
wo broad
categories, thermoplastics and the
ermosets. Since thermop
plastics are capable of being softened by hea
ating and
hardened by
b cooling, tthey can be shaped into articles by
y operations
s such as m
molding or extrusion, wh
hich take
advantage of
o this capab
bility.
6.2.1. Plastics Additives
Add
ditives are incorporated into a thermo
oplastics com
mposition to achieve
a
speccific purposes during fa
abrication
or service.
s
The
e precise na
ature and am
mounts of th
hese additives depends on the plas
stic and its inherent
properties; the processing method used to convertt it to a finis
shed article; and any desired modific
cation of
properties to acchieve certain
n aesthetic, performance
p
e, or economic objectivess.
e main kinds of additives that may be
e used in therrmoplastic piiping compossitions includ
de the followiing:
The


zers. To prottect the plasttic against th
hermal degra
adation, particularly during processing
g.
Heat stabiliz

Antioxidants
s. To protectt against oxid
dation during
g processing and when in
n service.

and weathe
er-exposed service.

through dies and other surfaces.
s
Ultraviolet screens
s
or sttabilizers. To
o protect against ultraviole
et radiation in sunlight du
uring outdoorr storage
Lubricants. To facilitate
e and impro
ove fabricatiion by reducing viscositty and lesse
ening frictional drag

Pigments. To
T give the product
p
a disttinctive colorr.

ation of mate
erial and its properties.
p
homogeniza

Processing aids. To fa
acilitate mate
erial mixing and fusion during
d
proce
essing and thereby
t
optim
mize the
Property mo
odifiers. To enhance
e
a pa
articular prop
perty such as
s impact stre
ength or flexib
bility.
Fillers. Mos
st often used to reduce volume cost; however, fille
ers may also
o be used to increase stifffness or
to modify prrocessing ch
haracteristics
s.
Add
ditives are e
essential com
mponents of most thermoplastic piping composittions. They facilitate pro
ocessing,
enh
hance certaiin properties
s, give a product
p
a distinctive appearance and color, an
nd provide required
protection durin
ng fabricatio
on and service. There a
are only a few
f
thermop
plastics [e.g.., certain flu
uorinated
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poly
ymers such as polyviny
ylidene fluoriide (PVDF)] that do nott require the
e incorporatiion of some
e type of
add
ditive becaus
se they already have suffficient natura
al thermal sta
ability and ag
ging and wea
athering resis
stance.
The
e precise natture and qua
antities of add
ditives that can
c be used for piping co
ompositions are
a delimited
d by their
effe
ect on engin
neering properties, such as rigidity, impact stren
ngth, chemiccal resistanc
ce, creep res
sistance,
rupture strength
h under long
g term loading, and fatigu
ue endurance. For exam
mple, the use of an inorga
anic filler
can
n compromisse the natura
al resistance
e of polymers
s to very stro
ong acids orr bases. Also, too much filler, or
use
e of a filler o
of a coarser grade, or its inadequa
ate dispersio
on can introd
duce physic
cal discontinu
uities, or
inte
ernal faults, tthat can com
mpromise long term stren
ngth, ductility
y, toughness,, and fatigue
e endurance. Another
exa
ample is the excessive use of liquid
d stabilizers or lubricantts, which ten
nds to plastiicize the pla
astic and
thereby make it less creep
p-resistant an
nd more sen
nsitive to tem
mperature. Additionally,
A
the
t
propertie
es of the
se polymer used
u
in a pla
astics piping
g composition
n are not on
nly determine
ed by the ch
hemical elem
ments, or
bas
atoms, from wh
hich the pollymer is made, but are also profou
undly influenced by the specific geo
ometrical
angement by
y which the
e polymer’s atoms are combined
c
to
o form a ma
acromolecule
e. A most im
mportant
arra
molecular struc
ctural parameter is the length of the
e molecular chain. The longer the chain,
c
the larger and
avier the molecule.
hea
6.2.2. Crystallin
ne Thermop
plastics matterials
polymers, such as PE, PP,
P PB, and PVDF, are partly crysta
alline materials. Portions
s of their
Cerrtain other p
poly
ymer chainss organize th
hemselves in
n close and very
v
well ord
dered arrang
gements callled crystallite
es; other
porrtions lie in the amorpho
ous regions. The strong
ger physical bonds in th
he well-orde
ered, closely
y packed
crys
stalline regio
ons have sig
gnificant influence over mechanical properties ssuch as stre
ength, stiffne
ess, and
toughness. The
e extent of crystallization
c
n and the size and natu
ure of the crrystalline reg
gions, as we
ell as the
o molecules running from
m one crysta
alline region to another can all be
nature of the intterconnectivity network of
mewhat contrrolled by tailo
oring molecu
ular architectture.
som
6.2.3. Thermop
plastics Materials
polymers, such as PE, PP,
P PB, and PVDF, are partly crysta
alline materials. Portions
s of their
Cerrtain other p
poly
ymer chainss organize th
hemselves in
n close and very
v
well ord
dered arrang
gements callled crystallite
es; other
porrtions lie in the amorpho
ous regions. The strong
ger physical bonds in th
he well-orde
ered, closely
y packed
crys
stalline regio
ons have sig
gnificant influence over mechanical properties ssuch as stre
ength, stiffne
ess, and
toughness. The
e extent of crystallization
c
n and the size and natu
ure of the crrystalline reg
gions, as we
ell as the
nature of the intterconnectivity network of
o molecules running from
m one crysta
alline region to another can all be
som
mewhat contrrolled by tailo
oring molecu
ular architectture.
The
e many posssible variations in polymer structurre, combined with the different typ
pes and amounts of
add
ditives that ca
an be used, result in a great diversityy of plastic co
ompositions,, even within
n a particular polymer
group such ass polyvinyl chloride (PV
VC) or poly
yethylene (P
PE). The de
efining and classifying of such
mpositions iss, understand
dably, not a simple task.. The primary
y standard plastic
p
materrial specificattions are
com
issu
ued by the American Society for Testing
T
and Materials (A
ASTM). The first ASTM standards classified
c
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plas
stic materialss by a ‘‘Type
e, Grade, an
nd Class ‘system in acco
ordance with
h three key properties.
p
H
However,
with
h the growin
ng need to better
b
define
e plastic matterials by more than jusst three prop
perties, a nu
umber of
AST
TM standard
ds have adop
pted a cell classification system whe
ereby each o
of a number of
o primary properties
is given
g
a prope
erty cell number dependin
ng on the pro
operty value.
6.2.4. Cell classification
All the
t resultantt property cell numbers (tthere can be as many as
s needed) are
e then listed in a specified order.
Forr example in accordance
e with the ce
ell classification system of
o ASTM D3
3350, ‘‘Stand
dard Specific
cation for
Polyethylene Plastics
P
Pipe and Fitting Materials,’’ Class 2344
424 polyethyylene designates a mate
erial with
f within the
e following ra
ange of value
es:
properties that fall
Pro
operty
Require
ement
Den
nsity:
Cell 2 of
o property 1 [0.926 to 0.9
940 g/cm3]
Melt index:
Cell 3 of
o property 2 [_0.4 to 0.15
5 g/10 min]
xural modulu
us:
Flex
Cell 4 of
o property 3 [80,000 to _110,000
_
psi,, 550 to760 MPa]
M
Ten
nsile strength
h at yield:
Cell 4 of
o property 4 [3000 to _35
500 psi, 21 to
o _24MPa]
Res
sistance to slow crack
testt method B, Condition
C
C]
Cell 2 of
o property 5 [50 percent max failure after 24grow
wths: hrs, when using
Hyd
drostatic dessign basis
o property 6 [1600 psi orr 11 MPa] at 23_C
Cell 4 of
Alth
hough this ne
ewer cell-typ
pe format is a major imprrovement in classifying
c
and specifying
g piping matterials by
a broader
b
array
y of significa
ant property and perform
mance chara
acteristics, itt may not always be su
ufficiently
deffinitive predicctor of longe
er-term perfo
ormance prop
perties. The manufacture
er may have
e to be cons
sulted for
furtther information. For example, two PE
E materials w
with the same ASTM material cell cla
assification may
m have
stre
ength under long-term loading that re
esponds som
mewhat differrently to incre
easing temp
perature, or to
o fatigue
load
ding, or to ch
hemical environments.
A brief
b
description of the major
m
materrials used fo
or thermopla
astics piping follows. The
e Principle standard
s
pipiing products made from these
t
materiials, and theiir application
ns, are identiffied in Table
e 1.1. Nonsta
andard or
spe
ecialty piping products are
e also offere
ed from these
e materials.
7.
COMMONL
LY USED TH
HERMOPLAS
STIC PIPES
7.1. Polyvin
nyl Chloride
e (PVC) Pipe
e
PVC is used for potable
e water and drainage sys
stems. It is o
one of the most
m
widely u
used of the plastic
p
pipes.. It has a
erature rating
g and very po
oor resistanc
ce to solvents
s.
low pressurre and tempe
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In its virgin state PVC is
s a transluce
ent, colorless
s, rigid polym
mer. When PVC
P
was firstt commercia
alized it was softened
by the addition of plastiicizers, and the resultantt compositions were prim
marily used in the manuffacture of such items
as luggage
e, upholstery
y, garden ho
ose, wire co
oating, floor tiles, and laboratory
l
tu
ubing. Subsequent adva
ances in
extrusion an
nd molding e
equipment, and
a in the av
vailability of more
m
effectiv
ve stabilizer a
and lubricatio
on additives,, allowed
for the extrrusion of the
e much morre viscous, rigid compossitions which
h are the only ones suitable for piping. To
differentiate
e these new
wer UN plastticized comp
positions from
m the early plasticized versions
v
the
ey were iden
ntified as
UPVC, or rigid
r
PVC. Th
hese designations are still
s often use
ed. Of the co
ommonly ava
ailable therm
moplastics, riigid PVC
offers the highest
h
strength and stiffn
ness at the least
l
volume
e cost, which
h accounts fo
or its having become the
e leading
plastic mate
erial for both
h pressure and non-pressure piping. Major uses include wate
er mains; irriigation; drain
n, waste,
and vent (D
DWV); sewag
ge and draina
age; well cas
sing; electric conduit; and
d power and communicattions ducting
g. PVC is
available in a much broa
ader range of
o pipe sizes and wall thic
cknesses, fitttings, valves
s, and appurttenances tha
an in any
other plastic
c.
PVC piping is joined primarily by tw
wo techniques
s, solvent ce
ementing and
d elastomericc seals. Altho
ough it can be
b joined
f
its me
elt viscosity is
i too high fo
or making reliably strong joints under field conditio
ons.
by thermal fusion,
PVC piping
g is made on
nly from rigid compound
ds containing
g no plasticiizers and relatively sma
all quantities of other
ingredients.. To minimiz
ze adverse effects on long term strength and chemical re
esistance, minimal
m
quan
ntities of
additives arre used in prressure pipe
e compounds
s. To improvve impact strrength for co
onduit and otther applications that
may be sub
bject to mech
hanical abus
se, small qua
antities of sollid polymeric
c impact mod
difiers (but no
ot plasticizerrs, which
are generallly liquids) are sometime
es incorporatted into the composition. When imprroved stiffness is desired
d, filler—
generally ve
ery finely divvided calcium
m carbonate—
—is added. Combinations
C
s of these an
nd other additives can be
e used to
optimize a rigid
r
PVC co
omposition fo
or its intended
d application
n. The enhan
ncement of a particular property by th
he use of
additives may often require a trade-off with some
e other property. For the defining of rrigid PVC compositions based
b
on
resultant prroperties, AS
STM has es
stablished tw
wo material specification
ns based on
n the properrty cell class
sification
system. On
ne of these is
s ASTM D17
784, ‘‘Standa
ard Specifica
ation for Rigid Poly (Vinyyl Chloride) and
a Chlorina
ated Poly
(Vinyl Chlorride) Compo
ounds,’’ which
h classifies PVC
P
materia
als in accorda
ance with the nature of the
t polymer and four
primary pro
operties. The
ese four prop
perties are Base
B
resin, Im
mpact streng
gth, Tensile strength, Mo
odulus of ela
asticity in
tension, De
eflection tem
mperature un
nder load, an
nd Chemical resistance is the fifth property in addition to first four
properties. These prop
perties are classified
c
according to ccell system according to
o ASTM D1784 tables for PVC
materials.
Example for classificatio
on system ac
ccording to ASTM
A
D1784
4:
The manne
er in which a rigid PVC material
m
is ide
entified by th
his classificattion system is illustrated by a Class 12454-B
PVC materiial which, acc
cording to Ta
ables of AST
TM D1784, would
w
have to
o meet the fo
ollowing prop
perty requirem
ments as
following:
equirement
Property Re
Base resin:
Cell 1 of pro
operty 1 [poly (vinyl chlorride) photopo
olymer]
Impact stren
ngth N-m/mm
m] :
Cell 2 of pro
operty 2 [0.6
65 ft-lbf/in, minimum, 0.03
35
Tensile stre
ength:
Cell 4 of pro
operty 3 [7,0
000 psi, minim
mum or 48 MPa]
M
Modulus of elasticity in tension:
t
minimum]
Cell 5 of pro
operty 4 [400
0,000 psi, or 2.8 GPa
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Deflection temperature under load:
esistance:
Chemical re
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Cell 4 of pro
operty 5 [158
8_F (70_C), minimum]
m requireme
ents listed un
nder Suffix B in accordance to ASTM
M D1784
Must meet the minimum
pe is made from materia
als that mee
et the minimum requirem
ments of celll 12454-C, which,
w
to
Most PVC pressure pip
ong-term strrength, gene
erally is form
mulated with minimal qua
antities of prrocessing ad
dditives and property
maximize lo
modifiers.
For pressure pipe app
plications, th
he cell class
sification sys
stem of AST
TM D1784 is often com
mplemented by one
m
requ
uirement. All PVC pressu
ure pipe stan
ndards require that the p
pipe be made from a forrmulation
additional material
with a spec
cified minimu
um long-term
m strength tha
at has been established in accordancce with ASTM D2837, ‘‘S
Standard
Method forr Obtaining the Hydrosttatic Design Basis for Thermoplast
T
tic Pipe Matterials.’’ Standards for products
intended for the transpo
ort of potable
e water also
o require that the materia
al meet certa
ain minimum
m chemical extraction
e
requirements designed to protect wa
ater quality matching
m
with NSF 61 standard for potable
p
waterr (National Sanitation
S
Foundation Standard 61
1 for potable water).
Most ASTM
M and a num
mber of other PVC pressu
ure pipe stan
ndards identify PVC stress-rated materials by a four-digit
f
number, of which the ffirst two digitts designate
e its type and grade in accordance
a
o ASTM
with the older editions of
D1784 and the last two
o identify, in
n hundreds of pounds per
p square in
nch, the ma
aterial’s maxiimum recom
mmended
hydrostatic design stres
ss (HDS) for water at 73.4
4_F (23_C).
In accordan
nce with AST
TM conventio
on, the maxiimum HDS iss one-half th
he material’ss hydrostatic design basis
s (HDB),
which refers to the matterial’s long-tterm hydrosttatic strength
h (LTHS) ca
ategory when
n established
d in accorda
ance with
ASTM D283
37. The follo
owing list des
scribes the most
m
common
n PVC stress
s-rated mate
erials covered by this des
signation
system:
C 1120 is a Type 1, Grade 1 PVC material
m
(minimum cell cla
ass 12454-B)) with a max
ximum recom
mmended
1.
PVC
HDS of 2,00
00 psi (13.8 MPa.) for wa
ater at 73.4_F (23_C).
2.
PVC
C 2110 is a Type 2, Grade 1 PVC material
m
(minim
mum cell cla
ass 14333-D)) with a max
ximum recom
mmended
HDS of 1,00
00 psi (6.9 MPa).
M
3.
PVC
C 2116 is a Type 2, Grade
G
1 PVC
C material ((same minim
mum cell cla
ass as abov
ve) with a maximum
m
recommend
ded HDS of 1
1,600 psi (11
1 MPa).
Since by th
he ASTM con
nvention the maximum recommende
ed HDS is on
ne-half the m
material’s HD
DB, it follows
s that the
HDBs for th
hese materia
als are 4,000
0 psi (27.6 MPa),
M
2,000 psi (13.8 MPa), and 3,2
200 psi (22.1
1 MPa), resp
pectively.
The Plastic
cs Pipe Institute (PPI) listts a generic PVC 1120 fformulation that
t
providess for certain specified alternative
choices of ingredients a
and formulattion quantitie
es that have been determ
mined to allo
ow the formu
ulated compo
ounds to
h the short- a
and long-term
m requiremen
nts establish
hed for this material
m
classsification. Th
his formulatio
on, which
satisfy both
is listed in PPI TR-3, ‘‘Policies and
d Procedure
es for Develo
oping Recom
mmended Hyydrostatic Sttrengths and
d Design
or Thermopllastic Pipe Materials,’’ is periodica
ally updated to include any new alternate
a
choices of
Stresses fo
ingredients that have be
een validated
d by means of
o both short-term and long term testss.
P
materiall specification is ASTM D4396,
D
‘‘Stan
ndard Specification for Rigid Polyvinyl Chloride (P
PVC) and
The other PVC
Related Pla
astic Compo
ounds for No
on- Pressure
e Piping Prod
ndicated by its title, this specification
n covers
ducts’’ As in
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compounds
s only intended for no prressure uses
s. It is similarr to D1784 in
n that it is also based on
n the cell forrmat and
most of the same prima
ary classificattion propertie
es.
PVC pipe and fittings must conform to the follow
wing standard
ds:
1. ASTM D 1785, PVC Plastic Pipe, Schedules 40, 80, and 120
2. ASTM D 2241, PVC Pressure-Ra
ated Pipe (SDR Series)
3. ASTM D 2466, PVC Plastic Pipe Fittings, Sch
hedule 40
4. ASTM D 2467, Sockket-Type PVC
C Plastic Pipe
e Fittings, Sc
chedule 80
5. ASTM D 2665, PVC Drain, Waste and Vent Pipe
P
and Fittings
7.2. Chlorin
nated Polyv
vinyl Chlorid
de (CPVC) Pipe:
CPVC is us
sed for potab
ble water and
d drainage systems.
s
It ha
as the same characteristtics as those
e of PVC and
d is used
where a stro
onger piping system with
h higher pres
ssure and tem
mperature ra
atings is requ
uired.
As implied by its name
e, CPVC is a chemical modification
n of PVC. It is very sim
milar to PVC in many prroperties,
emperature. But the ex
xtra chlorine
e in CPVC’s
s chemical structure
s
including strength and stiffness at ambient te
increases this material’’s maximum operating temperature
t
limit by abo
out 50_F (28
8_C) above that for PVC
C. Thus,
CPVC can be used up to nearly 20
00_F (93_C)) for pressurre uses and up to about2
210_F (100_
_C) for non-pressure
applications
s. Principle u
uses for CPV
VC in addition
n to mentione
ed uses abo
ove (potable w
water and drrainage syste
ems) are
domestic ho
ot water and
d cold waterr piping, resiidential fire-ssprinkling pip
ping, and ma
any industria
al application
ns which
can take ad
dvantage of itts elevated-ttemperature capabilities and
a superiorr chemical re
esistance.
CPVC mate
erials are als
so classified
d by ASTM D1784.
D
Similar to PVC, most CPVC
C standards that cover pressurep
rated produ
ucts identifyy stress-rated materials by a four-d
digit numberr that comb
bines the old
der type an
nd grade
designation
n with the material’s
m
m
maximum
rec
commended HDS for water
w
at 73..4_F (23_C)).Currently, the only
recognized stress-rated
d CPVC desig
gnation is CP
PVC 4120, ssignifying a Type
T
IV, Gra
ade 1 materia
al in accorda
ance with
ASTM D178
84 with a ma
aximum reco
ommended hydrostatic
h
d
design
stress
s of 2,000 pssi(13.8 MPa)) for water at
a 73.4_F
(23_C) in accordance
a
w
with ASTM D2837.
D
In ad
ddition, mostt CPVC pipe
e standards that cover products
p
inte
ended for
elevated-tem
mperature sservice, such
h as for hot water piping
g, require th
hat the CPV
VC material have
h
no less
s than a
recommend
ded HDS of 5
500 psi (3.5 MPa)
M
(equiva
alent to an HDB
H
of 1,000
0psi or 6.9 MPa) for water at 180_F (8
82_C).
CPVC pipe and fittings must
m
conform
m to the follo
owing standa
ards:
e, Schedules 40 and 80 (IIPS)
1. ASTM F 441, CPVC Plastic Pipe
2. ASTM D 2846, CPVC
C Plastic Hot and Cold Water
W
Distribu
ution System
ms
3. ASTM F 439, Sockett-Type CPVC
C Plastic Pipe Fittings, Sc
chedule 80
ce with ASTM
M D1784
4. CPVC 4120material in accordanc
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7.3. Polyprropylene (PP
P) Pipe:
Polypropyle
ene is a pollyolefin simillar in properties to high
h-density PE
E but somew
what harder,, more temp
peratureresistant, an
nd lighter in weight, but less
l
tough. Itt is also simiilar to PE in its chemical resistance and
a heat fusiibility. As
in the case of PE, PP ca
an be joined to itself by socket
s
fusion, butt fusion,, and electro fusion.
Because off its greater stiffness and
d better tole
erance to ele
evated tempe
eratures PP=
= is sometim
mes chosen over PE
where these
e qualities are
a advantageous (e.g., for
f abovegro
ound piping and
a for the cconveying off hot fluids). Principle
applications
s for corrosivve drainage piping, for which
w
PP offe
fers better so
olvent resista
ance than eiither ABS orr PVC. A
product line
e of PP corrrosive draina
age piping made
m
from aflame-retard
a
dant grade of material is offered fo
or use in
laboratories
s and hospittals, and for chemical manufacturing
m
g. Another Principle
P
app
plication for PP is for co
onveying
corrosive ch
hemicals und
der pressure
e. For this ap
pplication, so
ocket fusion systems of p
pressure-rate
ed PP pipe and
a pipe
and fittings are availab
ble through NPS 6 (DN 150). At present there
e are no con
nsensus standards cove
ering PP
pressure pip
pe; all availa
able products
s are propriettary.
Polypropyle
ene materials are classiified by AST
TM D4101, ‘‘Standard Specification
S
for Polypro
opylene Mold
ding and
Extrusion Materials,’’
M
intto two types. Type I covers materials
s that have the
t highest rigidity
r
and strength
s
but that
t
offer
only moderrate toughne
ess. Type II covers
c
mate
erials (copoly
ymers of pro
opylene with ethylene or other olefins) which
tend to be le
ess rigid and
d strong but have
h
improve
ed toughnesss, particularly at lower te
emperatures. Both types are
a used
for pipe.
onitrile-Butad
diene-Styrene (ABS) Pipe:
7.4. Acrylo
ABS is wide
ely used as drainage pip
pe and is av
vailable in Sc
chedules 40 and 80 with plain or soc
cket ends. Jo
oints are
made by eitther solvent cement
c
or th
hreaded conn
nections. Only Schedule 80 can be th
hreaded.
ABS plastic
cs are made by combinin
ng styrene-a
acrylonitrile copolymers
c
w copolym
with
mers formed by reacting styreneacrylonitrile with butad
diene. The butadiene copolymers
c
impart toug
ghness, while the acry
ylonitrile cop
polymers
contribute strength,
s
rigidity, and ha
ardness. The
e result is a tough, relatiively strong plastic that is easy to mold
m
and
extrude.
amily coverss a wide rang
ge of materials. The pro
oportions of the
t basic co
omponents and
a the way in which
The ABS fa
they are co
ombined can be varied to
o produce a wide range of end prop
perties. A ma
ajor use of ABS
A
for pipe is in the
manufacturre of drain-w
waste-vent (DWV)
(
pipin
ng, for whicch it offers good rigidity
y, temperatu
ure resistance, lowtemperature
e toughness,, and the ability to make fast-setting ssolvent ceme
ented joints. ABS has been used for pressure
piping, prim
marily for water service applications,
a
but it has been
b
largely displaced b
by the strong
ger, more ch
hemically
resistant, an
nd more eco
onomical PVC
C. However, compressed
d-air piping made
m
from a proprietary extra-tough,, shatterresistant co
omposition is currently ma
arketed in Eu
urope and the United Sta
ates.
ABS materrials are clas
ssified by ASTM
A
D1788
8, ‘‘Standard
d Specification for Rigid
d Acrylonitrile-Butadiene
e-Styrene
(ABS) Plas
stics,’’ in acc
cordance with the cell class forma
at by which each of three properties—impact strength
(toughness)), tensile sttress at yielld (short-term
m strength), and deflec
ction temperature unde
er load (tem
mperature
resistance)—
—is accorde
ed a cell num
mber depending on the pro
operty value.
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The ASTM specification
n for ABS DW
WV pipe requ
uires that the
e material have a minimum cell classiification of ABS 2–2–
2, which sig
gnifies the fo
ollowing minimum properrties: notch im
mpact streng
gth of 2 ft-lb/iin (0.1 N-m/m
mm) of notch
h, 180_F
(82_C) defle
ection tempe
erature, and 4,000 psi (2..8 MPa) tens
sile strength.
ABS pipe and fittings must conform to ASTM Sta
andard D 2661, ABS Sch
hedule40 Pla
astic Drain, Waste,
W
and Vent
V
Pipe
and Fitting.
7.5. Polyeth
hylene (PE) Pipe:
This materia
al is widely used
u
for chem
mical drainag
ge piping sys
stems. PE pipe and fittings are manu
ufactured from
m flameretardant material
m
and are
a available
e in Schedule 40 or 80. Joining meth
hods include
e solvent cem
ment joints, threaded
t
joints, or me
echanical-typ
pe joints. (On
nly Schedule
e 80 can be tthreaded.).
Polyethylen
ne polymers used for piping are classified into
o three types: a low de
ensity, relativ
vely flexible form; a
medium-density, somew
what stiffer and
a less-flexible form; an
nd a high-de
ensity form, w
which is morre rigid and stronger.
s
m
of matterials of den
nsities lying around
a
the high
h
end of tthe medium density PEs
s and the
Most pressure pipe is made
lower end of
o the high-density materrials. This range has esta
ablished itse
elf as offering
g the best ba
alance of tou
ughness,
flexibility, an
nd long-term
m strength. No
o pressure pipe
p
is primarrily made from the more rrigid, higher--density mate
erials.
PE, which is somewhat less strong and less rigiid than PVC at ambient temperature
t
, is the second most use
ed plastic
ss, ductility, and
a flexibility
y, even at low
w temperatures. PE pipe
es do not
pipe material, primarily because of its toughnes
der the expa
ansive action
n of freezing
g water. In an
a emergenc
cy, smaller-d
diameter PE pipe scan be
b safely
fracture und
‘‘squeezed--off’’ (clampe
ed tightly) by
y suitable pro
ocedures, to shut down the
t flow of fluids. Also, PE
P pipe is much
m
less
prone to failure by a rap
pidly running crack.
ortant reasons why PE pipe is now
w used in ov
ver 85 perce
ent of all
These two last-named characteristtics are impo
w installations
s of piping fo
or gas distribu
ution.
current new
PE pipes also have sup
perior fatigue
e endurance. This featurre, plus their ability to da
ampen waterr hammer shock, has
led to their use for appliications such
h as ins ewer force mains
s, where rep
peated cyclic pressure ch
hanges tend to occur.
The high sttrain ability and
a fracture resistance of
o PE have le
ed to its sele
ection for use
e in unstable
e soils and situations
s
where axial bending and diametric
cal deflection
n are anticip
pated. Exam
mple installattions that utilize this fea
ature are
methane co
ollection systems for solid
d-waste sites
s, pipes insta
alled by direc
ctional trench
hless boring techniques, lake and
river crossin
ngs, and outffall pipes dis
scharging treated effluentt into seas an
nd oceans.
PE pipe is also
a
used forr the rehabilitation of old pipelines. Le
engths of PE
E pipe which have been joined to the required
length by th
he butt-fusion
n method are
e pulled, or sometimes
s
p
pushed,
insid
de the old lin
ne. New reha
abilitation pro
ocedures
have evolve
ed by which
h, for ease of
o insertion, the diamete
er of the liner PE pipe is reduced by a squee
eze-down
procedure, or by folding the pipe into
i
a U-sha
ape. Once in
nside the old
d pipe, the sstrain memo
ory in the ma
aterial is
relieved by a combination of heatin
ng and intern
nal pressure
e, allowing th
he PE pipe tto reground so that it fitts snugly
inside the existing
e
pipe.. The low stifffness of PE
E permits the coiling of sm
maller-diame
eter pipe [generally up to
o about 4
in (100 mm) although piipe up to NP
PS 6 (DN 150
0) diameter has
h been coilled for specia
al jobs]. The coiled length can be
hundreds of feet and so
ometimes ov
ver a thousan
nd feet (300 meters) long
g, depending
g on materiall, wall thickness, and
diameter. PE
P pipe is rea
adily heat-fus
sible and can
n be joined to
o it or to fittin
ngs by the bu
utt-fusion pro
ocess. PE fittings are
also availab
ble for joining
g pipe by the
e socket fusio
on and electrro fusion proc
cesses.
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For non-pre
essure buried
d pipe applic
cations, such
h as for storm
m water, roa
adway, and la
and drainage
e, various de
esigns of
profile wall construction
ns have been developed
d which enha
ance pipe wall
w stiffness while minim
mizing materia
al usage
ce, these pipe
es are displa
acing metallic
c drainage piping.
Because off their corrosiion resistanc
t PE polym
mer during prrocessing, sttorage, and service,
s
PE piping
p
compo
ain small qua
antities of
To protect the
ounds conta
heat stabilizers, antioxidants, and ultraviolet (UV)
(
screens
s or UV chemical stabiilizers. Black
k PE pipe materials
m
incorporate very finely divided carbon black as
a both a co
oloring pigment and to screen the polymer aga
ainst the
potentially damaging UV
U radiation in sunlight. Nonblack piping
p
compo
ositions inclu
ude a UV chemical
c
stabilizer in
sually tan or
o yellow forr gas, blue for water, a
and orange for commun
nications
addition to a coloring pigment (us
ducting).The primary specification for identifyin
ng and class
sifying PE piping
p
materials is ASTM
M D3350, ‘‘S
Standard
Specificatio
on for Polyeth
hylene Pipe and
a Fittings Materials. ‘S
Standard D33
350 employs the cell clas
ss format to cover
c
the
diversity of materials us
sed for pipin
ng. In additio
on, an ending
g code letter is used to designate th
he incorpora
ation of a
colorant and
d UV stabilizzer.
A recent ad
ddition to AST
TM D3350 is
s a new test for the class
sifying of PE’s resistance
e to crack gro
owth under sustained
s
tensile load
ding. The te
est method used for thiis purpose is ASTM F1
1473, ‘‘Notch Tensile Test
T
to Meas
sure the
Resistance to Slow Crack Growth off Polyethylen
ne Pipe and Resins.’’
350, most PE
E piping stan
ndards referrred to ASTM
M D1248, ‘‘Sttandard Spec
cification
Prior to the issuance off ASTM D 33
hylene Plastics Molding and Extrus
sion Materia
als,’’ for the
e defining of material requirements
r
s. ASTM
for Polyeth
D1248class
sified PE by
y type, repre
esenting the
e material’s density cate
egory, and g
grade, reflec
cting combin
nation of
properties, primarily the
e melt flow or processin
ng characterristics. Simila
ar to PVC, P
PE piping sttandards cla
assify PE
stress-rated
d materials b
by means of a four-digit number,
n
of which
w
the firs
st two digits refer to the older
o
type an
nd grade
designation
n and the last
l
two rep
present, in hundreds o
of pounds per
p
square inch, the material’s
m
m
maximum
recommend
ded hydrosta
atic design sttress (HDS) for
f water at 7
73.4_F (23_C
C). The follow
wing list describes the co
ommonly
used PE pip
ping materials in accorda
ance with this
s traditional d
designation system:
s
1.
PE 2406 is a Type
T
2 (i.e., medium-den
nsity), Grade 4 PE materrial, in accorrdance with ASTM
A
D124
48, which
ecommended
d maximum hydrostatic
h
d
design
stress
s of 630 psi (4.3 MPa), ffor water at 73.4_F (23_
_C). [The
carries a re
‘‘06’’ in the 2406designa
ates the 630 psi (4.3 MPa
a) design stress.]
2.
PE 3408 is a Type
T
3 (i.e.,, high-densitty), Grade 4 PE materia
al, in accord
dance with ASTM
A
D1248, which
carries a recommended
d maximum hydrostatic
h
de
esign stress of 800 psi (5
5.5 MPa) for water at 73.4
4_F (23_C).
To relate th
his older des
signation sys
stem to the newer cell system
s
of D 3350, the latter standa
ard includes a crossreference. The
T crossove
ers recognize
ed by the 1993edition of D 3350 are presented in
n following Ta
able 7.1.
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PE materia
al designation
n based on ty
ype and grad
dient
accordance
e with formerr ASTM D124
48, plus code
e for
material’s maximum reco
ommended hydrostatic
h
design
stress for water, for 73
3_F
Correspond
ding minimum
m cell classifiication in
accordance
e with cell cla
assification sy
ystem of
ASTM D
D3350
PE 2406
3333
PE 213
PE 3406
4433
PE 324
PE 3408
4434
PE 334
Table 7.1
8.
DESIGN AN
ND INSTALL
LATION
Thermoplas
stics are visc
coelastic ma
aterials; thus
s they exhibit a profoundly different stress-strain
n and stress
s-rupture
response th
han do elasstic materials
s. Nonethele
ess, elastic e
equations us
sed for othe
er types of piping
p
are frrequently
applicable to
t thermopla
astics piping, provided that their eng
gineering be
ehavior is re
epresented th
hrough apprropriately
derived valu
ues of apparrent modulus
s and strength.
e properties are greatly
y influenced by the histo
ory of the material’s
m
exxposure to stress
s
as we
ell as by
Since these
temperature
e and environment, pro
oper use of traditional elastic equa
ations requirres appropriately established or
estimated property
p
values.
Long-term strength
s
valu
ues for certaiin conditions
s [such as forr water at 73
3_F (23_C)] a
are available
e, and in som
me cases
(i.e., maxim
mum recomm
mended hydro
ostatic desig
gn stress) the
ey may even
n be part of tthe product standard.
s
In addition,
some code
es and suggested design protocols either list o
or give proce
edures for arriving
a
at appropriate values
v
of
strength, stiffness, and allowable strrain. As this is a still dev
veloping technology, not all
a properties
s for all mate
erials are
ardized basis
s.
yet available in a standa
is either
However, for
f the more
e frequently used materrials, sufficie
ent informatio
on for the m
majority of applications
a
available or may be ad
dequately es
stimated. Wh
hile the visc
coelasticity of
o thermoplasstics somew
what complic
cates the
s
app
propriate ma
aterial consta
ants, materials with high strain
s
capaciity help to fac
cilitate design. Under
process of selecting
a great many conditions thermoplas
stics display
y a ductile lik
ke behavior: They are ab
ble to deform
m significantlly before
his behavior helps to red
distribute strresses and preclude faillure by locallized stress intensificatio
on which
fracture. Th
could initiatte cracking in brittle like
e materials. Within certain limits, design of the
ermoplastics piping is based
b
on
average stress; localize
ed stress concentrations are
a generallyy ignored.
Also, as prreviously poiinted out, th
he strain cap
pacity of the
ermoplastics under consstant strain (where
(
stres
sses can
gradually decrease
d
thro
ough stress relaxation) is often significantly gre
eater than that under constant
c
load
d (where
stresses inttensify as th
he material deforms). Allowable
A
strrain limits un
nder constan
nt strain can
n therefore often be
greater than
n the fracture strains obs
served unde
er sustained loading. Forr example, se
everal investtigations of PVC
P
and
PE pipes su
ubjected to constant
c
deflections overr long periods of time sho
ow that the m
materials did
d not fail at sustained
s
strains of as
a high as fro
om 5 to 10 percent.
p
The
ese same strains corresp
ponded to re
elatively short lifetimes when
w
the
materials were
w
subject tto constant lo
oad.
One simpliffication comm
monly employed in the North America
an design of flexible burie
ed plastic pip
pes (the word
d flexible
in this instance signifies
s that the pip
pe can underrgo significan
nt permanent deformation
n without cra
acking) assumes that
oading (resultting largely in
n pipe bending stresses relieved by both
b
pipe
internal pressure (consttant load) and external lo
n and stress relaxation) are
a acting ind
dependently.
deformation
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That is, the pipe wall thickness is ch
hosen on the basis of inte
ernal fluid pre
essure, and tthen a separrate analysis
s is made
hat the pipe is sufficienttly strong and structurally
y stable und
der the exterrnal loads ac
cting alone. In
I effect,
to ensure th
localized fib
ber stresses due to bendiing and other external loa
adings are neglected.
Standard in
nstallation practices include recomm
mendations for
f avoiding localized sttress concentrations. Fo
or cases
where locallized strain cannot
c
be av
voided and where
w
it mayy thus limit de
esign, more rigorous des
sign protocols based
on a combin
ned loading analysis
a
are available.
m
potenttial factors that could ca
ause a mate
erial with apparent high strain capac
city to shift from
f
the
There are many
ductile like to
t the brittle like state an
nd as a resullt, fail at lowe
er-than-expe
ected strains.. These can include temp
perature,
environmen
nt, duration of
o loading, nature
n
of loa
ading (unreliieved or relieved by stre
ess relaxatio
on), stress triaxiality,
fatigue, sca
ale factors (ssuch as walll thickness), damage (cu
uts, gouges)), stored ene
ergy in syste
em (such as residual
stresses fro
om manufaccture), material imperfec
ctions (voids
s, contamina
ants), polym
mer aging, and
a
chemica
al attack.
Judging from the good track record
d that exists, these influe
ences, althou
ugh difficult tto quantify, appear
a
to ha
ave been
ses by standards, design
n protocols, and
a installatio
on practices.. In addition, material
adequately considered ffor typical us
ovements hav
ve been evolving that ensure greaterr durability in pipe produc
cts.
requirements and impro
e, design practices
p
giv
ve recognitio
on to the effects
e
on strength
s
and
d stiffness and
a
other lo
ong-term
Furthermore
engineering
g properties by
b time, temp
perature, and
d environme
ent.
Finally, insttallation reco
ommendation
ns address many
m
of the u
unique chara
acteristics of plastics thatt can affect structural
s
integrity and
d durability. To
T be sure, the
t state of the
t art of thermoplastics piping is still evolving, an
nd considera
able work
yet remains
s to be accom
mplished to further
f
define
e materials properties
p
an
nd performan
nce limits. Such work is ongoing,
and for the latest inform
mation the re
eader is enc
couraged to refer to the growing literature, partic
cularly to the
e papers
presented at
a the various
s conference
es that addre
ess plastics p
piping techno
ology.
As demons
strated by the
e successful record of experience,
e
s
sufficient
info
ormation is a
available to successfully
y support
proper appllication of thermoplastics
s over a very
y broad rang
ge of engine
eering uses. To best realize the perfo
ormance
potential off thermoplasstics piping, the user should
s
base materials selection
s
and
d utilize des
sign and ins
stallation
practices on informatio
on, such as standards and
a
recommended practtices, which has been developed
d
under the
crutiny of the
e consensus process of an
a establishe
ed profession
nal society orr technical as
ssociation, as well as
technical sc
upon the recommendatiions and reports issued by
b industry and independ
dent sources.
duction to some
s
of the more basic
c aspects of
o the design
n and installlation of
The following material is an introd
More detailed
d recommend
dations suita
able to a partticular producct and situation should be sought
thermoplasttics piping. M
and followed.
M.Kamall
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COMMON DESIGN
D
AN
ND INSTALLA
ATION CON
NSIDERATIO
ONS
9.1. Interna
al Hydraulic Pressure
Thermoplas
stic pipe is prressure rated
d by means of
o the ISO
Where:
PR
=
pipe
e pressure ra
ating, psi (MPa)
t
=
min
nimum wall th
hickness, in (mm)
Dm
=
mean diameter, in (mm)
HDS
=
DB x DF, whe
ere HDB is in
n psi (MPa) units
u
and DF
F is the pipe design
d
factorr
HD
ermined for each pipe ty
ype and lifetime, Figure 9.1 showing
g determining
g HDB for PVC
P
1120 pip
pe as an
HDB is dete
example.
Fig. 9.1
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Values of HDS
H
for water at 73 F o (2
23 C o) are sp
pecified by most
m
ASTM and
a other sta
andards that cover water and gas
applications
s. The maxim
mum HDS fo
or water is generally
g
determined by
y multiplying the material’s HDB by a design
factor (DF) of 0.5. In selecting th
he appropria
ate design fa
actor, consid
deration is g
given to two
o general groups of
conditions.
ers the man
nufacturing and
a
testing variables,
v
sp
pecifically no
ormal variatiions in the material,
The first grroup conside
manufacturre, dimension
ns, quality of handling tec
chniques, and the accura
acy of the lon
ng-term stren
ngth predictio
on.
The second
d group con
nsiders the application or use, spe
ecifically installation, environment, temperature
t
, hazard
involved, life
e expectancy
y desired, an
nd the degree of reliability
y selected.
For gas pip
pe, a DF of 0.32 is pres
scribed by th
he federal ccode. Certain
n other code
es and stand
dards (e.g., those of
AWWA) ma
ay prescribe specific design factors.
A DF smalller than 0.5
5 is used in
n applications where gre
eater compe
ensation is a
advisable for certain an
nticipated
conditions (e.g.,
(
surges
s or tempera
ature), or wh
here the fluid
d conveyed may have ssome effect on the pipe material
properties. The final dettermination of
o the approp
priate DF for any given application is up to the dis
scretion of the design
engineer.
ng that a pipe
e’s outside diameter is eq
qual to Dm _ t, the previo
ous equation takes the following form:
By assumin
Where:
DR
=
Ratio off average ou
utside pipe diiameter to minimum
m
wall thickness.
9.1.1. Surge Prressure
ansient and regularly
r
rec
curring surge
e pressures may cause damage
d
to p
pipe and fittings by eithe
er of two
Tra
pos
ssible effectss: The surge exceeds the
e short-term fracture
f
stren
ngth of the p
pipe or one of
o the compon
nents; or
(and this is the more likely possibility) th
he repetitive
e changes in pressure exxceed the fattigue endura
ance limit
t
pipe or some
s
piping component. Transient o
or water ham
mmer surgess result from
m sudden cha
anges in
of the
velo
ocity. The prressure rise caused
c
by th
he velocity ch
hange can be
e estimated by means off the same equations
e
use
ed for calcula
ating the effe
ects of waterr hammer in other pipes. The only d
difference is that
t
with pla
astics the
app
propriate matterial modulu
us is that for the condition
n of dynamic
c, instantaneous respons
se (about 150
0,000 psi
(1.0
0 GPa) and 4
460,000 psi (3.2
(
GPa) for high-densitty PE and PV
VC, respectivvely, at 73_F
F (23_C)). In cases of
netw
work piping it is suggeste
ed that a com
mplete netwo
ork analysis be performe
ed for more accurate
a
estimates of
pos
ssible surge pressures.
p
Bec
cause of the
e lower stifffness of pla
astics, the surge pressu
ure rise thatt occurs from
m water hammer is
sign
nificantly low
wer than for metallic piping. For exa
ample, the surge pressure rise for each
e
foot-per-second
cha
ange in flow velocity is frrom about 16
6 to 20 psi (110
(
to 140 kPa)
k
and 8 tto 12 psi (55
5 to 83 kPa) for PVC
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and
d PE, respec
ctively, at 73_
_F (23_C). The
T exact va
alue depends
s on pipe wa
all thickness , the thicker the wall,
the larger the prressure rise.
As noted previiously, if the
ere I no dam
mage accrue
ed by exces
ssive fatigue
e, thermopla
astic pipes have
h
the
cap
pability to withstand mom
mentary press
sures that are
e significantly greater tha
an the pipe’ pressure
p
rating.
This
s is due to th
he stress verrsus time-to--failure chara
acteristics of thermoplasttic pipe mate
erials. Howev
ver, if the
sum
m of short-te
erm pressure
e rise plus the
t
sustaine
ed working pressure
p
excceed the pip
pe’s short-term burst
stre
ength, failure
e will result.
Enttrapped air in a pipeline can produc
ce sudden ac
ccelerations of air-separrated water columns.
c
The kinetic
ene
ergy of these
e fast-moving
g columns can
c sometimes be high enough
e
to fra
acture the pipe.
p
For this
s reason,
whe
en plastic piping system
ms are first fiilled with wa
ater, either fo
or operation or testing, they
t
should be filled
carefully and relatively slowly to minimiz
ze air entrapm
ment.
Airr should be vented
v
from the high poiints before th
he system is
s pressurized
d. Other precautions sho
ould also
be taken, such
h as carefullly laying pip
pe to grade or using aiir vent-vacuu
um relief lin
nes, to minim
mize the
entrapment of air
a in operatin
ng pipelines.
Wh
hen there exis
sts a frequen
ntly recurring
g pressure su
urge of signifficant amplitu
ude— say, over 25 perce
ent of the
ope
erating press
sure—the designer sho
ould evaluate
e the piping
g for adequ
uacy of fatig
gue enduran
nce. The
resistance to fatigue
f
varie
es from mate
erial to matterial. For example, PE pipe is quite tolerant; modern
matterials can withstand
w
fre
equent surgin
ng up to one
e-half of the pipe pressu
ure rating ev
ven when the
e pipe is
ope
erating at its full rating ba
ased on only static pressu
ure considera
ations.
In the
t case of P
PVC pipe, which
w
is some
ewhat more sensitive to effects of fatigue, the following equa
ation has
bee
en proposed for estimatiing the maxiimum total hoop
h
stress, due to both
h static and cyclic pressure, that
PVC
C pipe can ssafely tolerate
e as a functio
on of the tota
al number off anticipated surge pressu
ure events:
Wh
here:
=
S
0.0069)
C
=
maximum allowable to
otal hoop strress, psi (no
o safety facttor) (for S_ in MPa, mu
ultiply by
er of cycles
total numbe
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Table 9.1
Sugg
gested Maxim
mum Sustain
ned Working Pressures for
f Water for 73_F
(23_C) for
f Schedule 40 and Sche
edule 80 PVC Fittings
Sch
hedule 40
Schedule 80
Required
min
nimum
burst pressure
by ASTM
D24
466 psig
Maximum
suggested
working
p
pressure
psig
Required
minimum
m
burst press
sure
by ASTM
M
D2467 psig
Ma
aximum
suggestted working
press
sure psig
¹⁄₂
1
1910
358
2720
509
³⁄₄
1
1540
289
2200
413
Nominal size, in
1
1
1440
270
2020
378
1¹⁄₄
1
1180
221
1660
312
1¹⁄₂
1
1060
198
1510
282
2
890
166
1290
243
2¹⁄₂
970
182
1360
255
3
840
158
1200
225
3¹⁄₂
770
144
1110
207
4
710
133
1040
194
5
620
117
930
173
6
560
106
890
167
8
500
93
790
148
10
450
84
600
140
12
420
79
580
137
Note: This
s table is on
nly intended as a genera
al guide. Ap
ppropriate ma
aximum worrking pressures may varry widely
depending on specific fitting
f
design
n and field co
onditions, pa
articularly wh
hen repetitive
e surge pres
ssure are pre
esent as
ng-term strength becaus
se of fatigue effects. The
e fitting manu
ufacturer sho
ould be cons
sulted for
these may lower the lon
dations.
recommend
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9.2. Resista
ance to Vac
cuum and Ex
xternal Pres
ssure
The perrformance off flexible pipe
e with thin wa
alls that is made from ma
aterials with low
l
modulus
s of elasticity can
sometim
mes be limite
ed by bucklin
ng under vacuum or exterrnal pressure
e.
A net ex
xternal presssure can resu
ult from external hydrosta
atic loading, from interna
al negative prressure, from
m the
tempora
ary vacuum tthat may acc
company pre
essure surgin
ng, or from a combination
n of these ele
ements.
The buc
ckling resista
ance of plasttic pipes may
y be estimate
ed using the following adaptation of th
he elastic buckling
equatio
on for thin tub
bes:
Where:
Pc
E
I
v
Dm
C
critical buck
kling pressurre, psi (MPa))
=
apparent modulus
m
of ela
asticity, psi (MPa) (For sh
hort-term loa
ading conditio
ons, use the values
=
of E and
d as obtaine
ed from shorrt-term tensile
e tests; for lo
ong-term load
ding, approp
priate values as
determiined from lon
ng-term loading tests sho
ould be employed)
=
pipe wall moment of ine
ertia, in4/in (m
mm4/mm)
atio (approximately 0.35 to 0.45 for lo
ong-term loading)
=
Poisson’s ra
mean diameter, in (mm)) _ diameter to centroid of
o pipe wall fo
or profile wall pipe
=
Ovality corrrection factorr, (r0/r1)3, wh
=
here r1 is the
e major radiu
us of curvature of the ova
alized
pipe, an
nd r0 is the radius assum
ming no ovaliz
zation
e of solid wa
all constructio
on, for which I = t3/12, the
e previous eq
quation is ussually expressed as follow
ws:
For pipe
Where
t
=
all thickness, in (mm)
pipe wa
Accordiing to this eq
quation, pipe made to a constant
c
ratio
o of diameterr to wall thick
kness has the
e same resis
stance to
hydraulic collapse, independent
i
t of pipe diam
meter.
For burried pipe, the
e stiffening efffect of embe
edment can ssubstantially increase the
e buckling ca
apacity. This is
discuss
sed in section
n 11. CONSIIDERATIONS
S FOR BELO
OWGROUND
D USES.
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9.3. Tempe
erature Effec
cts
As the system temp
perature incrreases, therm
moplastics p
piping becom
me less rigid,, exhibits hig
gher impact strength,
s
ers lower sh
hort- and long
g-term strength. The opp
posite effects
s take place
e as tempera
ature decreas
ses. The
and offe
exact effect depend
ds not only on
o material cllass but its specific
s
comp
position. For example, th
here are PEs
s suitable
for serv
vice at temp
peratures as high as aro
ound 160_F (71_C); wh
hereas otherr PEs might only have sufficient
s
strength
h through ab
bout 120_F (4
49_C). In the
e case of fittings, wall thic
ckness and p
product design also influence the
effects of temperatu
ure on streng
gth.
The bes
st way to de
etermine the effect of tem
mperature on
n long-term strength
s
is through stress
s-rupture testing. PPI
TR-4, ‘‘Recommen
nded Hydros
static Strengths and D
Design Stres
sses for Th
hermoplastic
c Pipe and Fittings
ded HDBs fo
or various co
ommercial grade
g
thermo
oplastics for temperature
es up to
Compounds,’’ lists recommend
(
200_F (93_C).
Becaus
se of its effec
ct on stiffness, increasing
g temperaturre also decre
eases the colllapse resista
ance of plasttics pipe.
Table D 9.2 lists approximate te
emperature de
d rating facto
ors for some
e of the more
e commonly used
u
materia
als.
This efffect is in direct proportion
n to the change in the ma
aterial’s appa
arent modulu
us of elasticity
y. This modu
ulus
change
es with tempe
erature at a rate
r
roughly parallel
p
with the strength de rating fac
ctors given in
n Table D 9.2
2.
Other principal
p
effec
cts to be con
nsidered in piping design and installattion are those resulting frrom thermop
plastics’
high coefficient of expansion and contraction
n.
Some potential
p
conssequences to be conside
ered include:
1. Piping that is installed hot
h may cool sufficiently after
a
installattion to genera
ate substantial tensile forrces.
onnection sho
ould be made after the pipe has equilibrated to am
mbient, or to
o the desired
The final co
temperature
e.
2. Unrestraine
ed pipe may shrink
s
enoug
gh to pull outt from elastomeric gaskett or compres
ssion joints. The
T pipe
should be adequately
a
re
estrained by the use of anchors, or th
he fitting shou
uld be design
ned to eitherr resist
pull-out forc
ces or to tole
erate the max
ximum anticip
pated pipe movement.
m
3. Piping expo
osed to cyclic
c temperaturre changes m
may be susce
eptible to fatiigue damage
e at points su
ubject to
repetitive be
ending.
4. Pipe installe
ed when amb
bient temperratures are lo
ow may buck
kle if the com
mpression forrces developed on
subsequentt pipe expansion are not adequately relieved.
r
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Table 9.2
Efffect of Temperature on
n Strength a
and Stiffness
s of Thermo
oplastics Pip
pe: Approximate Temp
perature D rating
Factors
Tempe
erature
10.
PVC
(F
F)
P
PE
PEX
PB
Type 1
CPVC
PVDF
7
70
1
1.0
1.0
1.0
1.0
1.0
1.0
80
0
0.95
0.95
5
0.97
0.88
—
0.93
90
0
0.90
0.91
1
0.92
0.75
—
0.87
10
00
0.80
0
0.87
7
0.86
0.62
0.78
0.82
110
0
0.75
0.83
3
0.82
0.50
—
0.76
12
20
0.70
0
0.79
9
0.77
0.40
0.65
0.71
130
0
0.50
0.76
6
0.72
0.30
—
0.65
14
40
0.40
0
0.73
3
0.68
0.22
0.50
0.61
150
0.20
0.69
0.69
NR
—
0.57
160
NR
0.66
6
0.58
NR
0.40
0.54
180
NR
0.63
3
0.48
NR
0.25
0.47
2
200
NR
0.50
0
0.40
NR
0.20
0.41
2
220
NR
NR
R
NR
NR
NR
0.38
2
250
NR
NR
R
NR
NR
NR
0.35
2
280
NR
NR
R
NR
NR
NR
0.28
CONSIDER
RATIONS FO
OR ABOVEG
GROUND US
SES
Thermoplas
stic piping syystems in ab
boveground service
s
mustt be properly
y supported to avoid exc
cessive stres
sses and
sagging. Va
alves and other heavy piping compo
onents should
d be individu
ually supportted. Piping should
s
be loc
cated, or
protected, to
t avoid me
echanical da
amage. The piping layo
out should have
h
sufficie
ent flexibility or other means
m
of
mitigating excessive
e
bending and ax
xial stresses and fatigue effects induc
ced by repetiitive expansion-contractio
on.
10.1. Supp
ports and An
nchors
Horizontal runs
r
require the use of hangers
h
thatt are carefullly aligned an
nd are free o
of rough and
d sharp edge
es. Many
hangers de
esigned for m
metal pipe arre suitable fo
or thermopla
astic pipe as
s well. These
e include the
e shoe, clam
mp clevis,
sling, and roller
r
types. To
T preclude high localize
ed support p
pressures, it is generally advisable to
o modify the hangers
by increasin
ng the bearin
ng area by in
nserting a pro
otective sleev
ve of plastic between the
e pipe and the hanger.
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Vertical line
es must also be supporte
ed at intervals to reduce loads on the
e lower fitting
gs. This can be accomplished by
using riser clamps or do
ouble bolt cllamps locate
ed just below
w a coupling or other fitting to support the pipe. When
W
so
ese provide the necessarry support witthout excess
sive compres
ssion of the p
pipe.
located, the
Anchors are
e used in th
hermoplastic piping syste
ems as fixed
d points from
m which to d
direct expansion-contrac
ction and
other movements in a defined
d
direc
ction. Their placement is selected to prevent
p
overrloading of th
he piping, pa
articularly
w
pipe movement
m
co
ould generate excessive bending and
d axial stress
ses.
at changes of direction where
Anchors sh
hould be plac
ced as close
e to elbows and tees as
s possible. Guides
G
are u
used to allow
w axial motion while
preventing transverse
t
m
movement. Both
B
anchors and guides may be use
ed in the conttrol of expan
nsion and contraction
of pipelines
s. They should be of a sty
yle and be so
o located as to prevent overstressing
o
g of the pipe. A flexibility analysis
can be used
d to determin
ne suitable arrangements
a
s for anchors
s and guides.
10.2. Support Spacing
g
Support spa
acing require
ements are computed
c
us
sing the sam
me beam defflection equa
ations used for
f metal pip
ping. The
minimum spacing
s
requ
uirement can result from either maximum allo
owable stresss or maxim
mum allowable pipe
deflection consideration
c
ns for the maximum
m
antticipated serv
vice tempera
ature. Maxim
mum beam deflection,
d
or sag, is
frequently th
he controlling
g factor. Typ
pical support spacing reco
ommendations are prese
ented in Table 10.1.
When the piping
p
layout does not inc
clude sufficient changes in direction, appropriate
a
e
expansion loops or offsetts have
to be provid
ded. The size
e of the loops
s and offsets
s depend on the design (s
see Fig. 10.1
1), and the ch
hange in length of
pipe that ha
as to be acco
ommodated. The dimensions of loops
s and offsets are calculatted using the
e following eq
quation
for cantileve
ered beams loaded at on
ne end.
Where:
L
=
loop len
ngth, in (mm))
E
=
modulu
us of elasticity
y at the work
king tempera
ature, psi (MP
Pa)
S
=
maximu
um allowable
e stress at the working temperature, psi
p (MPa)
Do
=
outside pipe diametter, in (mm)
L
=
change
e in length du
ue to tempera
ature change
e, in (mm)
Assuming a maximum allowable
a
stra
ain of 0.01, as
a suggested
d by a plastic
cs industry publication, th
he above equ
uation
reduces to:
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10.3
3. Expansion-Contractio
on
There are several
s
metho
ods used forr controlling or
o compensa
ating for axial and bendin
ng stresses caused
c
by the
ermal
expansion. Piping runs may include changes in direction whiich will allow
w the thermally induced le
ength change
es to be
afely. Where this method is employed
d, the pipe must be able to
t float excep
pt at anchor points.
taken up sa
When the piping
p
layout does not inc
clude sufficient changes in direction, appropriate
a
e
expansion loops or offsetts have
to be provid
ded. The size
e of the loops
s and offsets
s depend on the design (s
see Fig. 10.1
1), and the ch
hange in length of
pipe that ha
as to be acco
ommodated. The dimensions of loops
s and offsets are calculatted using the
e following eq
quation
for cantileve
ered beams loaded at on
ne end.
FIGURE 10.1
e thermal strresses by tra
ansforming th
hem to bendiing stresses. The minimu
um loop stren
ngth L is
Expansion loops relieve
ge
enerally dete
ermined by th
he maximum
m allowable bending
b
stresss or strain.
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Because the fitting restrrains the pipe
e, a separate
e check shou
uld be made with the man
nufacturer re
egarding the fitting’s
capacity to absorb expa
ansion-contra
action stresses and bend
ding moments
s. Expansion
n joints of bellows and pis
ston
designs are
e available an
nd sometime
es used. How
wever, piston
n expansion joints for presssure applica
ations are ge
enerally
expensive. Proper alignment of pisto
on joints is critical to prevvent binding. Bellows type joints can accept some
e lateral
movement.
Table 10.1
Pipe
Dimensiion
Nominaal
diam., in
i
PVC
C
60"F
1000"F
CPV
VC
140"F
60"F
100"F
PVDF
140"F
1800"F
80"F
PP
1
100"F
140"F
3¹⁄₂
3³⁄₄
4
—
4¹⁄₂
4¹⁄₂
2
2¹⁄₂
2¹⁄₂
—
2¹⁄₂
2¹⁄₄
160"F*
600"F
100"F
140"F
180"F
1³⁄³⁄₄
2
2
2¹⁄¹⁄₂
2¹⁄¹⁄₂
3
3¹⁄¹⁄₂
4
1³⁄₄
2
2
2¹⁄₄
2¹⁄₂
2¹⁄₄
2¹⁄₄
3¹⁄₄
1¹⁄₂
1³⁄₄
2
2
2¹⁄₄
2¹⁄₂
3
3¹⁄₂
1¹⁄₄
1³⁄₄
1³⁄₄
2
2
2¹⁄₄
2³⁄₄
3
Wall Schedule 40
¹⁄₂
³⁄₄
1
1¹⁄₄
1¹⁄₂
2
3
4
6
8
4¹⁄₂
5
5¹⁄₂
5¹⁄₂
6
6
7
7¹⁄₂
8¹⁄₂
9
4
4
4¹⁄₂
5
5
5
6
6¹⁄₂
7¹⁄₂
8
2¹⁄₂
2¹⁄₂
2¹⁄₂
3
3
3
3¹⁄₂
4
4¹⁄₂
4¹⁄₂
5
5¹⁄₂
6
6
6¹⁄₂
6¹⁄₂
8
8¹⁄₂
9¹⁄₂
4¹⁄₂
5
5¹⁄₂
5¹⁄₂
6
6
7
7¹⁄₂
8¹⁄₂
4
4
4¹⁄₂
5
5
5
6
6¹⁄₂
7¹⁄₂
2¹⁄⁄₂
2¹⁄⁄₂
2¹⁄⁄₂
3
3
3
3¹⁄⁄₂
4
4¹⁄⁄₂
3³⁄₄
4
4¹⁄₄
—
4¹⁄₂
4¹⁄₂
Wall Schedule 80
¹⁄₂
¹⁄₄
1
1¹⁄₄
1¹⁄₂
2
3
4
6
8
5
5¹⁄₂
6
—
6¹⁄₂
7
8
9
10
11
4¹⁄₂
4¹⁄₂
5
—
5¹⁄₂
6
7
7¹⁄₂
9
9¹⁄₂
2¹⁄₂
2¹⁄₂
3
—
3¹⁄₂
3¹⁄₂
4
4¹⁄₂
5
5¹⁄₂
5¹⁄₂
6
6¹⁄₂
—
7
7¹⁄₂
9
10
11
5
5¹⁄₂
6
—
6¹⁄₂
7
8
9
10
ontinuous su
upport reco mmended.
* Co
4¹⁄₂
4¹⁄₂
5
—
5¹⁄₂
6
7
7¹⁄₂
9
22¹⁄₂
2
2¹⁄₂
3
—
3
3¹⁄₂
3
3¹⁄₂
4
4
4¹⁄₂
5
4¹⁄₂
4¹⁄₂
5
—
5¹⁄₂
5¹⁄₂
4¹⁄₂
4¹⁄₂
4³⁄₄
—
5
5¹⁄₄
2¹⁄₂
3
3
—
3
3
2
22¹⁄₂
22¹⁄₂
3
3
3¹⁄₂
4
44¹⁄₂
2
2¹⁄₂
2¹⁄₂
2³⁄₄
3
3¹⁄₄
4
4¹⁄₂
2
2¹⁄₄
2¹⁄₄
2¹⁄₂
2³⁄₄
3
3¹⁄₂
4
1¹⁄₂
2
2
2¹⁄₂
2¹⁄₂
2³⁄₄
3¹⁄₂
3¹⁄₂
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CONSIDER
RATIONS FO
OR BELOWG
GROUND US
SES
Design and installation of
o thermopla
astic pipe for belowground
d uses recog
gnizes its ‘‘fle
exible’’ condu
uit behavior. As
noted earlie
er, the word fflexible prima
arily signifies
s that the pipe has the ca
apacity to susstain significa
ant deflection
n without
failure. Although this value is somew
what arbitrary
y, a pipe is o
often conside
ered flexible iif it can susta
ain 2 percentt
deflection.
g and stiff an
nd that fail att low deforma
ations are cla
assified as riigid. Both rig
gid and flexib
ble piping
Conduits that are strong
ke advantage of soil sup
pport to miniimize interna
al stresses and
a must be designed and installed to avoid
systems tak
stress conc
centrations a
and deformattions that co
ould result in excessive localized stre
esses. Thus, the installe
ed buried
pipe is actu
ually a pipe-ssoil system, with both the
e pipe and the soil contrributing to the structural performance
e. This is
an importan
nt concept fo
or all types off buried pipin
ng systems.
Designing pipe
p
for burie
ed conditions
s may be diffferent for pre
essure pipe and
a non presssure pipe. The
T stresses induced
by internal pressure arre often high
h relative to those in non pressure pipe, and th
he stresses in
i pressure pipe are
constant (subject to cre
eep), while th
he strains in non pressu
ure pipe are constant (su
ubject to rela
axation, i.e., stresses
relax with time).
t
In addition, when
n subjected to internal pressure,
p
a pipe reroun
nds, reducing
g the deflec
ction and
bending stre
esses that re
esult from ea
arth loading.
Thus, for many
m
pressu
ure pipes, a design that meets the requirementts of the inte
ernal pressu
ure condition
n can be
considered adequate fo
or buried app
plications, pro
ovided the p
pipe is properly installed in good-quality backfill materials.
m
Although all designers should satisfy themselv
ves to this through calc
culation che
ecks, in gene
eral, if the following
f
conditions are
a met, a prressure pipe
e design may
y be conside
ered adequatte for burial without
w
chec
cking the cap
pacity for
earth and liv
ve loads:
1. Minimum
m depth of cover of 3 ft (1 m) for live lo
oads up to th
he magnitude
e of an AASH
HTO H20 truck.
2. Maximum
m depth of bu
urial of 20 ft (6
( m).
3. No unusu
ual concentra
ated or surch
harge loads exist.
e
4. Embedm
ment materials are granu
ular, stable, and
a compacted to at lea
ast 85 percent of maximum standard
d Proctor
density.
5. The pipe is uniformly supported on
o bedding th
hat is firm but not hard.
e is protected
d from concentrated loads
s at transitions from soil support to sttructural support, such as
s fittings,
6. The pipe
foundation penetrations
p
s, and other connections.
c
For non pre
essure pipe, and for pressure pipe no
ot meeting the just-noted criteria, the following conditions mus
st be met
in designing
g for earth loads:
1. The pipe should not d
deflect exces
ssively underr earth or live
e loads.
ximum wall compressive
c
s due to external loads.
2. The pipe should safely resist max
thrust forces
buckle in response to antticipated exte
ernal soil and
d hydrostaticc loads.
3. The pipe should not b
ding stresses
s that result from deflectiion.
4. The pipe should safely resist bend
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Because off the wide varriety of pipe wall profiles and material types, not all
a of these criteria will be
e significant for
f every
type of pipe
e; for instance
e, resistance
e to wall com
mpressive thru
ust forces is important fo
or profile wall pipe, but rarrely is
significant for
f solid-wall pipe.
11.1. Pipe-S
Soil System
m Parameterrs
The behavio
or of pipe-so
oil systems is
s controlled by
b two param
meters:
The hoop sttiffness para
ameter SH
The bending stiffness pa
arameter SB
B
b
ratios off the soil stifffness to the pipe
p
stiffnesss. An elasticity solution fo
or pipe embe
edded in an infinite
These are both
elastic media was developed by Burrns and Rich
hard23 and utilizes these two parameters to descrribe buried pipe
behavior.
op stiffness parameter
11.1.1. The hoo
e hoop stiffne
ess paramete
er is defined as:
The
Wh
here:
SH
=
hoop stiffne
ess paramete
er
Ms
=
constrained
d modulus off soil, psi (MP
Pa)
H
PSH
=
pipe hoop stiffness
s
para
ameter, psi (M
MPa)
The
e pipe hoop stiffness
s
para
ameter is defined as:
Wh
here:
E
=
pipe material modulus of
o elasticity, psi
p (MPa)
A
=
ength of pipe
e, in2/in (mm
m2/mm)
pipe wall arrea per unit le
R
=
radius to ce
entroid of pip
pe wall, in (mm)
e pipe hoop stiffness
s
para
ameter repre
esents the ch
hange in pipe
e diameter th
hat results frrom a radial pressure
The
app
plied to the perimeter
p
as shown in Fig. 11.1. Thiss change in diameter ressults from a reduction in the pipe
circ
cumference d
due to the ax
xial compress
sive stress p
produced by the
t loading.
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Fig.11.1 Pipe ho
oop stiffness
s
11.1.2. The bed
dding stiffne
ess parametter
e bending stiffness param
meter is defin
ned as:
The
Wh
here:
SB
=
bending stifffness param
meter
Ms
=
constrained
d modulus off soil, psi (MP
Pa)
B
PSB
=
pipe bendin
ng stiffness parameter,
p
ps
si (MPa)
The
e pipe bendin
ng stiffness parameter
p
is defined as:
Wh
here
I
=
pipe wall moment of ine
ertia per unit length, in4/in
n (mm4/mm))
The
e pipe bendin
ng stiffness parameter
p
re
epresents the
e change in diameter
d
thatt results from
m a concentra
ated
load
d as demonsstrated in Fig
g. D11.2.This
s deformation
n results from
m flexural strresses produ
uced by the
con
ncentrated lo
oading.
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Fig.11.2 Pipe ben
nding stiffnes
ss
In general:: The hoop sstiffness para
ameter represents a ratio
o of the soil stiffness
s
to th
he pipe exten
nsional stiffness, and
the bending
g stiffness pa
arameter rep
presents the
e ratio of the
e soil stiffnes
ss to the pipe flexural stiffness. In a detailed
analysis the
e Poisson’s rratio of the so
oil and the pipe
p
material are also imp
portant; howe
ever, since most
m
design methods
are based on
o simplified models of behavior, and
d most pipe installation is
s completed b
by relatively crude metho
ods, very
little accura
acy is lost by
b ignoring this parame
eter. The co
ontribution of
o each of tthe hoop an
nd bending stiffness
parameters
s to the overa
all pipe soil system is imp
portant and b
bears discuss
sion.
12.
PE / METAL PIPE TRA
ANSATION FITTING
F
ping materiall undergroun
nd on the site
e is high-density polyethyylene (HDPE) with heat-fu
used
The most offten used pip
butt joints. Socket-type
S
jjoints in large
e sizes have
e often been found to dev
velop unacce
eptable stress in the pipe. The
lower the sttandard dime
ension ratio (SDR)
(
the hig
gher pressurre rating of pipe.
p
Therefore, care mus
st be taken to
o select
the correct SDR pipe.
d not permiit plastic pipe
e to be run aboveground,, thus Piping above ground shall
Commonly in process fields, codes do
herefore a tra
ansition fitting
g from plastic pipe to metallic pipe is required, conforming to ASTM
A
D2517 , s
be metal; th
shown on figure 11.3 Tyypical transition fitting.
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Asrequired
Metallic
c pipe
Epoxy coated
2'-0"
0.6m
Grade
n-bonded epox
xy
Fusion
coated
d, steel casing
g
Buttt fused
90° PE elbow
2'-0"±
0.6m
1
1'-0"
0.3 m
0
12"
" PE pigtail
0.3
3 m
Epoxy-co
oated bolt on
steel mou
unting stake
Concrete
e
Fig.11.3 Typical
T
trans
sition fitting
12.1 Examp
ple, Vendor Print for PE
E / Metal Tra
ansition Fittiing
Lyall (Vendor’s Name) is the only manufacturer that
t
offers tw
wo distinct tra
ansition sealing methods allowing a la
arger
onfigurations
s to meet you
ur requirements. Our one
e-piece, facto
ory assemble
ed transitions
s provide saffe,
choice of co
economical and easy-to
o-install conn
nections betw
ween gas carrrying steel pipe
p
and polyyethylene (PE
E) pipe.
Proven Relliability - bo
oth designs have been approved
a
by most naturall gas, propan
ne and indus
strial fluid com
mpanies
with over 4 million in service.
Features
• Meets or exceeds
e
all in
ndustry requ
uirements.
• Epoxy or primer
p
coatin
ngs available
e.
• Fusion bonded epoxy coating prov
vides superio
or resistance to corrosion
n and mechan
nical damage
e.
• All welded
d joints are 10
00% pressurre tested.
• Meets of exceeds
e
the requirements of ASTM D2513
D
catego
ory 1, ASME
E B 31.8, US CFR 49 Part 192.
• Listed with
h IAPMO/UP
PC and certifiied to CSA B137.4
B
Two types of
o sealing are
e available as
a shown on following figu
ure 11.4
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Figure 11.4
4
Connection
n Options:
Steel End Options
O
•
SCH 40
0 (standard) or SCH 80
•
Primer or other coa
atings
•
Interna
al Fusion Bon
nded Epoxy Coating
C
(Victaulic Groove
e and Thread
ded O.D. sea
al models on
nly)
PE Pipe En
nd Connections/Options
s
•
Square
ed ready for fusion
f
•
Sockett fusion fitting
g
•
LYCOF
FIT ® Mecha
anical Fitting (PE size up to 2 IPS)
•
Many choices
c
of HD
DPE and MD
DPE pipe
•
Comme
ercial/industrrial grade PE
E3408
Other Optio
ons
• Protector sleeves
s
• Anode
es
• Wire clips
• Steel to PVC PE pipe
p
(threade
ed O.D. only))
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PLASTIC-L
LINED PIPIN
NG FOR COR
RROSION RESISTANCE
E
Plastic-lined
d piping and fittings cons
sist of a meta
al housing lined with chem
mically resisttant plastic. The
T combina
ation of a
chemical-re
esistant engin
neered plastic liner inside
e a relativelyy inexpensive
e but mechan
nically strong
g pipe or fittin
ng
housing allo
ows for the ssafe and econ
nomical conv
veyance of ccorrosive and
d dangerous chemicals. For
F this reaso
on,
plastic-lined
d pipe finds widespread
w
u in such in
use
ndustries as the chemica
al process, pulp and pape
er, and meta
al
finishing ind
dustries. It is also the des
sired choice when
w
produc
ct purity is off concern, pa
articularly wh
hen metal corrrosion
by-products
s cannot be ttolerated in th
he process fluid. Industries requiring such purity a
are pharmac
ceuticals, foo
od,
power gene
eration, and electronics,
e
t name a few
to
w.
When service conditions
s are within the
t capabilitiies of a plasttic-lined pipin
ng system, it is often an economical
e
t expensive
e alloy piping. The methods of lining vary,
v
but all achieve
a
the same
s
goal: to
o ensure thatt the
alternative to
liner and ho
ousing expan
nd and contra
act as one un
nit, even though plastic and
a metal ha
ave greatly diiffering rates of
expansion and
a contraction.
13.1. History
d pipe was first manufacttured in the early
e
1940s a
and sold com
mmercially in 1948.
Plastic-lined
The first pip
ping system was
w made by
y mechanica
ally reducing or swaging a steel tube housing
h
dow
wn onto an ex
xtruded
polyvinylide
ene chloride (PVDC)
(
resin
n liner. Initiallly, plastic-lin
ned pipe was
s not widely a
accepted by the chemica
al
processing industries be
ecause the PVDC
P
liner could only be used for acids and causstics to a max
ximum servic
ce
e of 175_F (7
79_C). As ne
ew high-perfo
ormance ressins and diffe
erent manufacturing techn
niques were
temperature
developed, plastic-lined pipe was taken more se
eriously as a cost-efficient method of ffighting corro
osion.
h
standard
ds developed
d by the vario
ous manufac
cturers in the
e plastic lined
d pipe industry and more than 50
Thanks to high
years of suc
ccess in veryy aggressive applications
s, plastic-line
ed pipe is a proven
p
and accepted piping product wherever
w
corrosive ch
hemicals must be convey
yed.
13.2. METH
HODS OF MA
ANUFACTURE
The plastic--lined pipe in
ndustry uses both extrusio
on technique
es for melt-ex
xtrudable typ
pe resins or sintering
s
metthods for
processing polytetrafluo
oroethylene (PTFE)
(
powd
der resins intto their final forms. Sinte
ering can be defined as fo
orming a
coherent bo
onded mass by heating a powder wiithout melting it. The following sectio
ons provide a brief descrription of
the type of processing
p
u
used
by the various
v
manu
ufacturers off plastic-lined
d piping products.
13.2
2.1. Liner Manufacturin
ng Processe
es for PTFE Liners
Alth
hough PTFE
E fluorocarbon resins are
a thermopllastic materials, they do not flow readily as do
d most
thermoplastics. Instead whe
en PTFE me
elts at 647_F
F (342_C), it changes fro
om a white solid
s
to a transparent
rubbery gel. Be
ecause of th
he extremely
y high viscos
sity of the melted
m
PTFE
E, special tec
chniques ha
ave been
dev
veloped for cconverting grranular PTFE
E resins to fin
nished produ
ucts. The bassics steps co
ommon to all of these
tech
hniques are
● Compaction
C
o the granullar resin at a relatively lo
of
ow temperatu
ure into a co
ompressed fo
orm so that iti can be
han
ndled
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● Heating
H
of th
he compacte
ed resin abo
ove its meltin
ng temperatture (commo
only called sintering)
s
so that the
poly
ymer particle
es can coales
sce into a strrong homoge
eneous struc
cture
● Cooling
C
of the
e sintered prroduct at a controlled
c
ratte to room te
emperature tto achieve th
he desired degree
d
of
crys
stalline deve
elopment
Voids caused by
b insufficient consolida
ation of PTF
FE resin parrticles during
g performing may appea
ar in the
shed articless. With referrence to a te
emperature, for example
e 73_F (23_
_C), PTFE-lin
ner specific gravities
finis
belo
ow 2.11 indic
cate a high-v
void content. The minimu
um accepted standard sp
pecific gravity
y as defined in ASTM
F 1545 for PTF
FE-lined pipe
e is 2.14. Although void content is determined
d
largely by pa
article charac
cteristics
and
d performing conditions, sintering co
onditions can
n also have an effect. Sintering at to
oo high or to
oo low a
tem
mperature can
n increase vo
oid content.
13.3. Liner Materials
ng materials fall into two
o main cate
egories: fluorrinated plasttics and no fluorinated plastics. Flu
uorinated
Plastic linin
plastics are
e fully fluorinated, as in
n the case of polytetra
afluoroethylen
ne (PTFE), perfluoroalk
koxy, and pe
er fluoro
ethylene propylene,
p
o
or partially fluorinated,
f
as in the case of etthylenete tra
a fluoro eth
hylene (ETF
FE) and
polyvinylide
enefluoride. It is the fluoriine-carbon bonding
b
of th
hese materials that provid
des the outsttanding resis
stance to
chemical attack. In facct, the fully fluorinated plastics exh
hibit better chemical
c
ressistance than
n virtually any other
cluding otherr metals, plas
stics, or com
mposites. The
ey also posse
ess:
material, inc
● High therm
mal stability
● Resistanc
ce to sunlight degradation
n
● Low smok
ke and flame
e characteristics
● Resistanc
ce to fungus and bacteria
a build-up
They generrally have:
● Low perm
meability to m
most gases and liquids
● High puritty in the virgiin form
● Process ability,
a
forma
ability, and mold ability
● Cold weather impact strength
s
asion resistan
nce
● High abra
● Low coeffficients of fricction
● Approval for food contact use
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13.3.1. Liner Ty
ypes








Polytetrrafluoroethylene (PTFE).
Fluorina
ated Ethylene Propylene (FEP).
Perfluoroalkoxy (PF
FA).
Ethylen
netetrafluoroe
ethylene (ET
TFE).
Polyvinylidene Fluo
oride (PVDF).
Polypro
opylene (PP)).
Polyvinylidene Chlo
oride (PVDC)).
Polyeth
hylene (PE).
uorinated pla
astics, polyp
propylene (P
PP) and poly
yvinylidene chloride
c
(PVDC), are mo
ore general purpose
The non flu
materials th
hat provide g
good overall chemical res
sistance. The
ey have lowe
er temperatu
ure and chem
mical resistance than
the fluoro polymer and are
a generally
y less expens
sive.
omparisons
13.4. Installled Cost Co
Specificatio
on of a corro
osion-resistan
nt piping sys
stem is a co
omplex assig
gnment, if forr no other re
eason than the
t large
number of available
a
ma
aterials that vary
v
both in cost
c
and perrformance. The materialss-selection ph
hase usually
y yields a
number of piping
p
candid
dates that will perform ad
dequately from a technica
al standpointt. Then a cho
oice is made from the
candidates on an econo
omic basis. Three
T
types of
o cost comparisons are common:
c
Material cos
st
Initial installled cost
Long-term life-cycle cos
st.
Many speciifiers limit the
eir economic
c analysis to
o materials costs only be
ecause they are relatively
y simple to estimate.
e
Yet this ap
pproach pose
es a very re
eal danger because
b
it ig
gnores what is often we
ell over half of the true required
investment for a piping system,
s
that is, the in-pla
ace cost of th
he system, in
ncluding fabrrication and installation co
osts.
Many types
s of corrosio
on-resistant piping have relatively high material costs beca
ause they arre supplied from
f
the
manufacturrer in the fo
orm of prefa
abricated co
omponents. This, however, makes these mate
erials relativ
vely less
expensive to
t install.
Conversely, many piping systems with
w low mate
erial costs oftten require th
he additionall expense of fabrication at
a the job
site prior to installation.
A widely us
sed formatte
ed study9 prresents a co
omparison o
of initial insta
alled costs ffor a broad variety of co
orrosionresistant pip
ping systemss. It provides
s the engine
eer with a sc
creening tool to help narrrow the field
d of candidates for a
piping proje
ect so that a final deta
ailed econom
mic study ca
an be made
e on the spe
ecific piping arrangemen
nt under
consideratio
on. Factors considered in the study
y are: type of
o piping used, material costs, com
mplexity of th
he piping
system, fab
brication and erection tec
chniques, an
nd labor rates and productivity in insttallation. Tab
ble 13.1 sum
mmarizes
the installed
d cost ratios from the mo
ost recent pu
ublication forr a NPS 2 (D
DN 50) complex piping sy
ystem. The report
r
list
cost ratios are for NP
PS 2, 4, and
d 6 (DN 50, 100, and 150) piping layouts forr both straig
ght-run and complex
nts. A plastic
c-lined metallic piping sys
stem offers clear
c
advanta
ages over bo
oth metal an
nd solid-plasttic piping
arrangemen
systems. Compared to a piping sys
stem consistting of corrosion resistan
nt metal, pla
astic-lined pip
pe provides equal or
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better resis
stance to che
emical attack, depending
g on liner m
material. Whe
en comparing
g the installe
ed cost of a flanged
plastic-lined
d metallic pip
ping system to a welded
d metallic pip
ping system, the plastic lined system
m is often low
wer. See
Table 13.1. This is espe
ecially true when
w
comparing plastic-lin
ned pipe to metal
m
system
ms of higher alloy
a
materia
als.
de from the same
s
materrial as the plastic liner, p
plastic-lined pipe provide
es higher
Compared to a plastic system mad
pabilities as w
well as highe
er mechanica
al strength. Plastic-lined
P
piping syste
ems are also
o available in
n a wider
service cap
range of lin
ne sizes, with a broade
er selection of fittings, when
w
compa
ared to solid
d thermoplas
stic or therm
mosetting
systems.
d pipe is not only used where
w
chemic
cal attack is a concern, it is also used
d where med
dia contact with
w metal
Plastic-lined
is detrimen
ntal, as in th
he case of ultra-pure chemicals
c
an
nd demonize
ed water ussed in variou
us processe
es in the
electronics industry.
Table 13.1
PIPING MA
ATERIAL COS
ST RATIOS
PVC (sch 80)
0.56
PT
TFE-lined FRP
3.20
CPVC
C (sch 80)
0.63
M
Monel (Sch 40)
3.24
Allloy 20 (Sch 40))
3.32
Carbo
on steel (Sch. 40
0)
1.00
Niickel (Sch 10)
3.34
304L S.S. (Sch. 10)
1.13
Haastelloy C-276 (Sch
(
10)
3.52
Rubb
ber-lined steel (S
Sch 40)
1.16
316L S.S. (Sch. 10)
1.20
PT
TFE-lined 304L SS (Sch 10)
4.12
304L S.S. (Sch. 40)
1.31
Niickel (Sch 40)
4.27
316L S.S. (Sch. 40)
1.45
Tiitanium (Sch 10)
4.46
Haastelloy C-276 (Sch
(
40)
4.46
FRP/v
vinyl ester
1.78
FRP/ epoxy
1.86
Haastelloy B (Sch 40)
5.71
FRP/ polyester
1.86
Ziirconium (Sch 10)
5.95
Polyp
propylene lined steel (Sch 40)
1.90
Saran lined steel (Sch
h 40)
1.91
Ziirconium (Sch 40)
4
7.04
PVDF
F-lined steel (Scch 40)
2.47
Alloy 20 (Sch. 10)
2.60
Monel (Sch 10)
2.61
Glass--lined steel (Sch
h 40)
2.69
PVDF
F (Sch 80)
2.71
PTFE
E-lined steel (Sch
h 40)
2.94
Titaniium (Sch 10)
2.99
FEP-llined steel (Sch 40)
2.99
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INSTALLAT
TION
e developme
ent of structu
ural design methods
m
for thermoplasttics, installattion practices
s dedicated to these
Concurrent with the
materia
als have als
so been de
eveloped. Noteworthy
N
a
among
thesse are AST
TM D 2774
4, ‘‘Undergro
ound Installlation of
Thermo
oplastic Pres
ssure Piping,’’ ASTM D 2321, ‘‘Und
derground In
nstallation off Thermoplasstic Pipe forr Sewers an
nd Other
Gravity--Flow Applic
cations,’’ and
d ASTM F 1668
1
‘‘Consttruction Proc
cedures for Buried Plasttic Pipe.’’ A commentary
y on the
installattion issues th
hat are critica
al to the long
g-term perforrmance of fle
exible no pre
essure plasticcs pipe has been offered
d by T. J.
McGratth.31 Howarrd has pub
blished a book
b
devote
ed to pipe installation issues.27 Installation as well as
s design
recomm
mendations are
a also iss
sued by varrious profess
sional and trade
t
associiations. A number of th
hese referen
nces are
identifie
ed in the follo
owing sectio
on. A significa
ant developm
ment in pipe installation practice is th
he use of co
ontrolled low--strength
materia
als (CLSM, also
a
known a
as flow able fill) for pipe backfill. CLS
SM is a mixtture of sand,, cement, fly ash, and water with
excellen
nt flow chara
acteristics su
uch that vibra
ation is not re
equired to pllace it around and underr a pipe or otther obstructtions in a
trench. Strengths are
a low, som
metimes as lo
ow as 35 ps
si (240 kPa) at 28 days, in order to assure that the materia
al can be
excavatted in the ev
vent that an e
encased utility requires a repair. In 19
997 ASTM held
h
a three-d
day symposiium on the subject of
CLSM, with many papers devvoted to its use around pipes.43 One
O
benefit of
o CLSM is that shrinka
age is minim
mal after
kfill an entire
e trench the settlement and
a pavemen
nt damage that often occ
curs with soil backfill
placement; thus, if used to back
can be avoided. Pip
pe installatio
on can be difficult if grou
und condition
ns are poor, and it is alsso expensive
e to provide full-time
inspectiion of pipe-la
aying crews. Therefore, a key step in quality co
ontrol of pipe
e installations is to check the pipe deflection
d
levels after
a
the insta
allation is com
mplete. This should be a standard pa
art of all pipe installation sspecifications.
15.
SOURCES OF ADDITIO
ONAL INFORMATION
ew Developments
15.1. On Ne
The inroads
s that therm
moplastics pip
ping has ma
ade in fuel g
gas distribution, sewer, water, agricultural, and highway
drainage, and
a
in various industrial uses has generated many
m
studie
es regarding
g the durability and eng
gineering
performanc
ce of these materials.
m
To
opics of partticular recentt interest rellate to the u
use of these materials fo
or largerdiameter ap
pplications fo
or which certtain limits of performance
e, such as maximum
m
dep
pth of burial, buckling res
sistance,
and compre
essive wall strength are often
o
design limiting. A re
eader interes
sted in these
e topics, as well
w as in the
e general
state of the art, should cconsult the proceedings
p
o the following periodica
of
ally held symposia and co
onferences:
Proceedings of Internattional Conferrences on Pipeline Desig
gn and Insta
allation, Ame
erican Societty of Civil En
ngineers,
345 East 47
7th Street, New York, NY
Y 10017.
Proceedings of the Sym
mposium on Buried Plas
stic Pipe Tec
chnology, Am
merican Society for Testting & Materrials, 100
Bar Harbor Drive, West Conshohock
ken, PA 1942
28.
Proceedings of the Fuel Gas Plastic
c Pipe Symposium, Amerrican Gas As
ssociation, 1515 Wilson Boulevard,
B
A
Arlington,
VA 22209.
erence on Fllexible Pipes
s, Center for Geotechniccal and Gro
oundwater Research,
Proceedings of the National Confe
Ohio Univerrsity, Athenss, OH 45701.
Proceedings of the International Conferences
C
on Plastics Pipe, Plasttics and Rub
bber Institute, 11 Hobart Place,
ngland SW1W
W OHL.
London, En
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15.2. Public
cations Rela
ated to Stan
ndards
The followin
ng publicatio
ons contain much
m
inform
mation that is
s useful for all
a applications of plastic
cs piping, pa
articularly
with respec
ct to design a
and installatio
on:
ASME Guid
de for Gas T
Transmission and Distribu
ution Piping Systems.
S
Av
vailable from American Society
S
of Me
echanical
Engineers, United Engin
neering Centter, 345 Eastt 47th Street, New York, NY 10017, (212) 705-7722.
AGA Plastic
c Pipe Manual for Gas Se
ervice. Availa
able from Am
merican Gas
Association
n, 1515 Wilso
on Boulevard
d, Arlington, VA
V 22209, (7
703) 841-845
54.
Maintenanc
ce of Operatiion of Gas Sy
ystems, Nov
vember, 1970
0, Army TM5
5–654;
NAVFAC-M
MO–220; Air Force AFM 91–6. Available from S
Superintendent of Docum
ments, U.S. Government
G
t Printing
Office, Was
shington, D.C
C. 20402.
15.3. Assoc
ciations
Various trad
de and technical associa
ations issue reports, manuals, and liists of refere
ences on pro
operties, des
sign, and
installation of plastics piping. A listing of current
c
litera
ature offering
gs may be obtained by
b contactin
ng these
organization
ns at the follo
owing addres
sses:
Thermoplas
stic pipe (ind
dustrial gas distribution,
d
sewerage, wa
ater, and gen
neral uses):
The Plastics
s Pipe Institu
ute, 1825 Co
onnecticut Av
ve., N.W., Su
uite 680, Was
shington, DC
C 20009.
Thermoplas
stics pipe (pllumbing app
plications): Plastics Pipe & Fittings Association,
A
8
800 Rooseve
elt Road, Bu
uilding C,
Suite 20, Glen Ellyn, IL 60137.
g (water disttribution, sew
werage, and
d irrigation): Uni-Bell
U
PVC
C Pipe Asso
ociation, 265
55 Villa Cree
ek Drive,
PVC piping
Suite 155, Dallas,
D
TX 75
5234.
‘‘No-Dig’’ methods
m
forr the rehabiilitation of existing
e
buriied pipelines
s: North Am
merican Soc
ciety for Tre
enchless
Technology
y, 435 North Michigan Av
venue, Suite 1717 Chicag
go, IL 60611..
15.4. Codes
s
Thermoplas
stics piping for
f plumbing
g, heating, co
ooling and ventilating,
v
sewer, water,, fire protecttion, gas distribution,
and other hazardous
h
m
materials may
y be subjectt to the provisions of a code
c
or othe
er regulation.. Nearly all plumbing
p
codes allow
w plastics pip
ping for certa
ain applicatio
ons. The ma
ajor model bu
uilding and p
plumbing cod
des from which most
such codes are derived are issued by
b the followiing organizations:
ng Code ,BO
OCA Nationa
al Mechaniccal Code, an
nd BOCA Na
ational Plum
mbing Code. Building
BOCA: Nattional Buildin
Officials and
d Code Adm
ministrators, In
nternational, Inc., 4051 W
West Flossmoor Road, Country Club Hills, IL 6047
78.
CABO: One
e and Two Family Dwe
elling Code. Council of American Building Officcials, 5203 Leesburg
L
Pik
ke, Falls
Church, VA
A 22041.
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IAPMO: Un
niform Plumb
bing Code. In
nternational Association
A
o Building and
of
a Mechaniccal Officials, 20001 Waln
nut Drive
South, Waln
nut, CA 9178
89–2855.
ICBO: Unifo
form Building
g Code and Uniform Me
echanical Co
ode. Internattional Conferrence of Building Officia
als, 5360
South Work
kman Mill Ro
oad, Whittier, CA 90601.
PHCC: Natiional Standa
ard Plumbing
g Code. Natio
onal Associa
ation of Plum
mbing Heating
g- Cooling Contractors,
C
P
P.O.
Box
6808, Falls Church, VA 22040.
SBCI: SBC
CCI Southern
n Building Co
ode, SBCCI Southern Standard Plum
mbing Code,, and SBCC
CI Southern Standard
S
Mechanicall Code. Southern Building
g Code Cong
gress Interna
ational, 900 Montclair
M
Road, Birmingh
ham, AL 35213.
American National
N
Sta
andards Insttitute
ANSI B31.3
3 Chemical P
Plant and Pettroleum Refinery Piping. Thermoplas
stic Piping AN
NSI B31.8 Gas Transmis
ssion and
Distribution Piping Syste
ems. ANSI Z223,
Z
Nationa
al Fuel Gas Code.
C
ndards and various jurisdictions an
nd authoritie
es require that
t
before pipe may be
b used forr certain
Some stan
applications
s, it first mu
ust be apprroved for th
hat use by a recognize
ed, or specifically desig
gnated, orga
anization.
Organizatio
ons and apprroval program
ms for plastic
c pipe include
e the followin
ng:
For potable
e water:
NSF Interna
ational, NSF Building, Po
ost Office Box
x 1468, Ann Arbor, MI 48
8106.
Canadian Standards
S
As
ssociation, 17
78 Rexdale Boulevard,
B
R
Rexdale,
Onta
ario,
Canada, M9
9W 1R3
For drain, waste,
w
and vent:
v
NSF Interna
ational and Canadian
C
Sta
andards Asso
ociation (see
e above).
For meat- and
a food-prrocessing pllants:
U.S. Departtment of Agrriculture, 14th
h and Indepe
endence S.W
W., Room0717 South, Wa
ashington, DC
C 20250.
For water pipe:
p
American Water
W
Works Association,, Denver, CO
O.
M.Kamall
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REFERENC
CES
1. Facts & Figures
F
of the
e U.S. Plasttics Industry (1997 edition
n),The Socie
ety of the Pllastic Industrry, Inc., Was
shington,
DC; ‘‘Resins Report,’’ Modern
M
Plasttics, January
y 1998.
ar, ‘‘Special Report:
R
Plastic to Remain
n Leading Piipe Material,’’ Plastics N
News, Februa
ary 19, 1990
0, p. 10.
2. Bill Brega
3. BCC Rep
port P-043N, ‘‘The Comp
petitive Pipe Market:
M
Matterials, Appliications Directions,’’ Business
Communica
ations Co., In
nc., Stamford
d, Connectic
cut.
4. L. E. Janson, Plastic Pipes for Wa
ater Supply and
a Sewage Disposal, Neste Chemiccals, Stenung
g- sund, Swe
eden,
Stockholm, 1989.
er, R.E. Chambers, and A.G.H.
A
Dietz
z, ‘‘Structural Plastics Des
sign Manual,,’’ ASCE Man
nual of Engiineering
5. F.J. Hege
Practice No
o. 63, Americ
can Society of
o Civil Engin
neers, New Y
York, May 19
984.
6. Section 18,
1 Soil-Therrmoplastic Pipe Interactio
on Systems, Standard Sp
pecifications for High- wa
ay Bridges,
of State Highway and
American Association
A
d Transporta
ation Officia
als (AASHTO
O), Washingtton, DC.
7. Stanley A. Mruk, ‘‘Th
he Durability
y of Polyethylene Piping,’’ STP 1093, Buried Plasttic Pipe Tech
hnology, Ame
erican
Society for Testing
, October 19
T
and
d Materials, Philadelphia
P
990.
8. P.E. O’Donoghue, M..F. Kanninen
n, C.H. Popla
ar, and M.M. Mamoun, ‘‘A
A Fracture M
Mechan- ic’s Assessment
A
of the
owth Test forr Polyethylen
ne Gas Pipe Materi- als,’’ Proceeding
gs of the Ele
eventh Plasttic Fuel
Battelle Slow Crack Gro
Gas Pipe Symposium,
S
O
October 3–5,, 1989, San Francisco, published by
y the America
an Gas Asso
ociation, Arlin
ngton,
Virginia.
9. X.R. Qian
n Lu, and N. Brown, ‘‘No
otchology—T
The Effect o
of the Notchin
ng Method o
on the Slow Crack
C
Grow
wth
Failures in a Tough Po
olyethylene,’’’ Journal of Materials
M
Sccience 26, 19
991, p. 26.
or Water Su
upply and Sewage Disp
posal,’’ Borea
alis, Sven Axelson
A
AB//Affisch
10. L.E. Janson, ‘‘Plasstic Pipes fo
& Reklamtry
yck AB, 1996
6.
11. Y.G. Hs
suan, ‘‘Evalua
ation of Stres
ss-Crack Re
esistance of P
Polyethylene
e Non-Pressu
ure Rated Re
esins,’’ study
y
conducted by
b the Geos
synthetic Res
search Institu
ute for the P
Plastics Pipe
e Institute, 19
997.
12. Y.G. Hs
suan, ‘‘A Stre
ess Crack Re
esistance Me
ethod for Eva
aluation of Po
olyethylene M
Materials Inte
ended for Pipe
Applications
s,’’ PPI reporrt published by Plastic Pipe Institute, Washing- to
on, DC. 1997.
13. L.E. Janson, ‘‘Plasttic Gravity Se
ewer Pipes Subject
S
to C
Constant Strrain by Defle
ection,’’ Proceedings of th
he
Internationa
al Conferencce on Underg
ground Plastiic Pipe, Ame
erican Society of Civil Eng
gineers, New
w York, March 1981.
14. A.P. Mo
oser, O.K. Sh
hupe, and R.R. Bishop, ‘‘Is PVC Pipe Strain Limite
ed After All These Yearrs?’’ STP 10
093,
Buried Plas
stic Pipe Tec
chnology, Am
merican Society for Testiing and Materials, October 1990.
15. H.W. Vinson, ‘‘Resp
ponse of PVC
C Pipe to Larrge, Repetitivve Pressure Surges,’’ Pro
oceedings off the Internattional
e on Undergrround Plastic
c Pipe, American Society of Civil Engineers, New York, March
h 1981.
Conference
M.Kamall
ne Design
Pipiing and Pipelin
Engineerr
A
MNI MBA
Subjecct.
Plaastic pipes for piping
p
Engineerring issues
ment.
Docum
Reesearch
Date.
277/12/2016
Page.
477 of 47
16. J.A. Bo
owman, ‘‘The
e Fatigue Re
esponse of Polyvinyl
P
Ch
hloride and Polyethylene
P
e Piping Systtems,’’ STP 1093,
Buried Plas
stic Pipe Tec
chnology, Am
merican Society for Testin
ng and Materials, Octobe
er 1990.
17. ‘‘PVC Pipe-Design
P
and Installa
ation,’’ AWW
WA Manual M
M23, Americ
can Water W
Works Assoc
ciation, 1980..
18. ‘‘AWWA
A Committee
e Report, Des
sign and Ins
stallation of Polyethylene
e Pipe Made
e in Accorda
ance with C 906,’’
9
American Water
W
Works
s Association
n (AWWA), 1998.
1
19. M.F. Ka
anninen, P.E. O’Donoghu
ue, J.W. Card
dinal, S.T. Green,
G
R. Cu
urr, and J.G. Williams,
‘‘A Fracture
e Mechanic’s Analysis of Rapid Crack
k Propagatio
on and Arrestt in Polyethyylene Pipes,’’’ Proceeding
gs of the
Eleventh Plastic
P
Fuel Gas
G Pipe Sym
mposium, Oc
ctober 3–5, 1989, Americ
can Gas Asso
ociation, Arlington, Virgin
nia.
20. R.D. Blliesner, Dessigning, Ope
erating and Maintaining PVC Piping
g Systems U
Using PVC Fittings,
F
PVC
C
Fittings Div
vision of the Irrigation As
ssociation, Arlington, VA, 1987.
21. R. Hall, ‘‘Design and Installation
n of Above Ground
G
Therm
moplastic Pip
ping System
ms,’’ Managin
ng Corrosion With
Plastics, vol. V, Nationa
al Association
n of Corrosio
on Engineerss, Houston, 1983.
22. M.W. Ke
ellog Compa
any, Design of
o Piping Sys
stems, John Wiley & Son
ns, New Yorkk, 1982.
23. J.Q. Burns and R.M. Richard, ‘‘A
Attenuation of
o Stresses fo
or Buried Cylinders,’’ Pro
oceedings of the Sympo
osium on
ure Interactiion, 1964, University of Arizona, Tucson, Arizon
na, pp. 378–3
392.
Soil Structu
24. T.J. Mc
cGrath, ‘‘Rep
placing E’ witth the Cons
strained Modulus in Burie
ed Pipe Dessign,’’ Pipelin
nes in the
Constructed
d Environme
ent, Proceediings of the Conference,
C
A
American
Society of Civil Engineers, 1998, Reston, VA.
25. E.T. Se
elig, ‘‘Soil Pa
arameters for Design off Buried Pip
pelines,’’ Pip
peline Infrasttructure Proc
ceedings of the
Conference
e, American Society of Civil
C Enginee
ers, 1988, Ne
ew York, NY
Y, pp. 99–116
6.
26. A.K. Ho
oward, ‘‘Mod
dulus of Soil Reaction
R
Values for Burried Flexible Pipe,’’ Jourrnal of the Ge
eotechnical
Engineering
g, ASCE, Vol 103, No. GT1,
G
1977, New
N
York, NY.
N
27. A.K. Ho
oward, Pipelin
ne Installatio
on, Relativity
y Publishing, Lakewood, CO, 1996.
28. N. Hash
hash, and E
E.T. Selig, ‘‘A
Analysis of the
t
Performa
ance of a Bu
uried High D
Density Poly
yethylene Pip
pe,’’
Proceeding
gs of the Firstt National Co
onference on
n Flexible Pip
ipe, 1994, Co
olumbus, OH
H.
29. N. Hash
hash and E.T
T. Selig, ‘‘Ana
alysis of the Performance
e of Buried High
H
Density Polyeth- yle
ene Pipe,’’ Structural
Performanc
ce of Flexible
e Pipes, Balk
kema, Rotterrdam, 1990.
30. T.J. McG
Grath, ‘‘Prop
posed Design Method for Calculating
g Loads and Hoop Comp
pression Stre
esses for Bu
uried
Pipe,’’ Repo
ort to the Po
olyethylene Pipe
P
Design Task Group
p of the AASHTO Flexible
e Culvert Liiaison Comm
mittee,
Simpson Gu
umpertz & H
Heger Inc., 19
990.
31. ASCE Manual
M
No. 60, ‘‘Gravity
y Sanitary Sewer
S
Desig
gn and Cons
struction,’’ American Soc
ciety of Civil
Engineers, New York, 1
1982.
32. AWWA,, ‘‘Fiberglass
s Pipe Desiign,’’ AWWA
A Manual off Water Sup
pply Practicces M45, American Wate
er Works
Association
n, Denver, C
CO, 1996.