ASTM F3534/F3534M-22

This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation:F3534/F3534M −22 An American National Standard
Standard Specification for
MRS-Rated Metric- and Inch-Sized Crosslinked Polyethylene
(PEX) Pressure Pipe for Gas Distribution Applications
ThisstandardisissuedunderthefixeddesignationF3534/F3534M;thenumberimmediatelyfollowingthedesignationindicatestheyear
of original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.
A superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope materialdesignationcode(forexamplePEXpipewithanMRS
of 8 MPa is called a PEX 80.
1.1 This specification covers crosslinked polyethylene
1.5 This standard does not purport to address all of the
(PEX) pipe that is outside diameter controlled in metric pipe
safety concerns, if any, associated with its use. It is the
sizes (DN 16 to 1000) and inch pipe sizes (NPS 3 to 54), and
responsibility of the user of this standard to establish appro-
pressure rated (see Appendix X1) using the MRS rating
priate safety, health, and environmental practices and deter-
system. This Specification is intended for PEX pipe made by
mine the applicability of regulatory limitations prior to use.
various processes, as long as the PEX pipe made by that
1.6 This international standard was developed in accor-
process meets all the requirements of this Specification. In-
dance with internationally recognized principles on standard-
cluded are requirements and test methods for material,
ization established in the Decision on Principles for the
workmanship, UV protection, dimensions, hydrostatic sus-
Development of International Standards, Guides and Recom-
tained pressure, stabilizer functionality, bent-pipe hydrostatic
mendations issued by the World Trade Organization Technical
pressure,chemicalresistance,minimumoperatingtemperature,
Barriers to Trade (TBT) Committee.
degree of crosslinking, squeeze-off, and hydrostatic burst
pressure. Requirements for pipe markings are also given. The
2. Referenced Documents
pipe covered by this specification is intended for natural gas
distribution.
2.1 ASTM Standards:
D543Practices for Evaluating the Resistance of Plastics to
1.2 This specification also includes requirements for quali-
Chemical Reagents
fying joints made using polyethylene electrofusion fittings
D618Practice for Conditioning Plastics for Testing
(such as Specification F3373) and PEX pipe. Fittings to be
D792Test Methods for Density and Specific Gravity (Rela-
used with PEX pipe manufactured to this specification are in
tive Density) of Plastics by Displacement
SpecificationF2829/F2829M.Installationconsiderationsarein
D1505Test Method for Density of Plastics by the Density-
X3.2.
Gradient Technique
NOTE 1—NPS fittings should not be used for DN sized pipe, and DN
D1598Test Method for Time-to-Failure of Plastic Pipe
sized fittings should not be used for NPS pipe.
Under Constant Internal Pressure
1.3 Thetextofthisspecificationreferencesnotes,footnotes,
D1599Test Method for Resistance to Short-Time Hydraulic
and appendixes, which provide explanatory material. These
Pressure of Plastic Pipe, Tubing, and Fittings
notes and footnotes (excluding those in tables and figures)
D1600TerminologyforAbbreviatedTermsRelatingtoPlas-
should not be considered as requirements of the specification.
tics
1.4 Units—The values stated in either SI units or inch-
D1603Test Method for Carbon Black Content in Olefin
pound units are to be regarded separately as standard. The
Plastics
values stated in each system are not necessarily exact equiva-
D2122Test Method for Determining Dimensions of Ther-
lents; therefore, to ensure conformance with the standard, each
moplastic Pipe and Fittings
system shall be used independently of the other, and values
D2290Test Method for Apparent Hoop Tensile Strength of
from the two systems shall not be combined.
Plastic or Reinforced Plastic Pipe
1.4.1 For consistency with ISO 9080, MRS values are only
D2565Practice for Xenon-Arc Exposure of Plastics In-
in MPa and degrees Centigrade for conversion to the pipe
tended for Outdoor Applications
1 2
This specification is under the jurisdiction ofASTM Committee F17 on Plastic For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Piping Systems and is the direct responsibility of Subcommittee F17.60 on Gas. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved Feb. 1, 2022. Published March 2022. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
F3534_F3534M–22 the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3534/F3534M−22
D2765Test Methods for Determination of Gel Content and 2.5 PPI Standards:
Swell Ratio of Crosslinked Ethylene Plastics PPITR-3HDB/HDS/PDB/SDB/MRS/CRSPolicies—Poli-
D4218Test Method for Determination of Carbon Black cies and Procedures for Developing Hydrostatic Design
Content in Polyethylene Compounds by the Muffle- Basis (HDB), Hydrostatic Design Stresses (HDS), Pres-
sure Design Basis (PDB), Strength Design Basis (SDB),
Furnace Technique
D5596Test Method for Microscopic Evaluation of the Minimum Required Strength (MRS), and Categorized
Required Strength (CRS) Ratings for Thermoplastic Pip-
Dispersion of Carbon Black in Polyolefin Geosynthetics
F412Terminology Relating to Plastic Piping Systems ing Materials or Pipe
PPI TR-4HDB/HDS/SDB/PDB/MRS/CRS
F2657Test Method for Outdoor Weathering Exposure of
Listed Materials, PPI Listing of Hydrostatic Design Basis
Crosslinked Polyethylene (PEX) Tubing
(HDB), Hydrostatic Design Stress (HDS), Strength De-
F2829/F2829MSpecification for Metric- and Inch-Sized
sign Basis (SDB), Pressure Design Basis (PDB), Mini-
Fittings for Crosslinked Polyethylene (PEX) Pipe
mum Required Strength (MRS), Categorized Required
F3203Test Method for Determination of Gel Content of
Strength (CRS) Ratings for Thermoplastic Piping Materi-
Crosslinked Polyethylene (PEX) Pipes and Tubing
als or Pipe
F3373Specification for Polyethylene (PE) Electrofusion
Fittings for Outside Diameter Controlled Crosslinked
3. Terminology
Polyethylene (PEX) Pipe
3.1 Definitions—Unless otherwise specified, definitions, ab-
2.2 Federal Standard:
breviations and initials are in accordance with Terminology
FED-STD-123Marking for Shipment (Civil Agencies)
F412 and Terminology D1600.
2.3 Military Standard:
3.2 Definitions of Terms Specific to This Standard:
MIL-STD-129Marking for Shipment and Storage
3.2.1 categorized required strength (CRS) or CRS (θ,t),
2.4 ISO Standards:
n—see ISO 12162 or PPI TR-4 for CRS definition.
ISO 1167Thermoplastics pipes, fittings and assemblies for
3.2.1.1 Discussion—TheMRSofacompoundisdetermined
the conveyance of fluids — Determination of the resis-
beforeaCRScanbedetermined.CRSisusedforadesigntime
tance to internal pressure — Part 1: General method
other than 50 years or a design temperature other than 20 °C.
ISO3126Plasticspipingsystems—Plasticscomponents—
An example of the use of CRS is provided in Appendix X2.
Determination of dimensions
3.2.2 design stress (σ ), n—stress equal to the MRS or CRS
ISO 9080Plastics piping and ducting systems — Determi- S
divided by the overall design coefficient (C).
nation of the long-term hydrostatic strength of thermo-
plastics materials in pipe form by extrapolation
σ 5 MRS ⁄ C or CRS ⁄ C (1)
s
ISO 12162Thermoplastics materials for pipes and fittings
3.2.3 material designation, n—as used in this standard, the
forpressureapplications—Classificationanddesignation
material designation for PEX pipe shall consist of the abbre-
— Overall service (design) coefficient
viation for the type of plastic (PEX) followed by two or three
ISO 13477Thermoplastics pipes for the conveyance of
Arabic digits, which are the MRS (in MPa only) times ten, as
fluids — Determination of resistance to rapid crack
shown in Table 1.
propagation (RCP) — Small-scale steady-state test (S4
3.2.4 maximum operating pressure (MOP), n—the esti-
test)
mated maximum pressure the pipe is capable of withstanding
ISO 13760Plastics pipes for the conveyance of fluids under
continuously with a high degree of certainty that failure of the
pressure — Miner’s rule ~ Calculation method for cumu-
pipe will not occur, as shown in the following equations that
lative damage
areusedinthisspecificationtorelatedimensions,designstress,
ISO 14531-1Plastics pipes and fittings — Crosslinked
and maximum operating pressure.
polyethylene (PEX) pipe systems for the conveyance of
gaseousfuels—Metricseries—Specifications—Part1:
Pipes
ISO 18553Method for the assessment of the degree of
pigment or carbon black dispersion in polyolefin pipes,
fittings and compounds
Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825,
Irving, TX 75062, http://www.plasticpipe.org.
TABLE 1 Material Designations for PEX Pipe
Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
Material Designation MRS (20 °C and 50 years) MPa
Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
Available from International Organization for Standardization (ISO), ISO
PEX 80 8.0
Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, PEX 100 10.0
Switzerland, https://www.iso.org.
F3534/F3534M−22
TABLE 3 Outside Diameters and Tolerances for NPS PEX Pipe
MOP 52σ ⁄ D ⁄ t 21,or
@~ ! #
S o
(2)
MOP 52σ ⁄ R 2 1 Tolerances for Maximum of
~ !
S
Average Outside
NPS Average Diameter absolute out-of-
Diameter in.
A
For MOP at a temperature other than 20 °C or a time (±) in. roundness in.
3 3.500 0.016 0.07
other than 50 years:
4 4.500 0.020 0.09
MOP 52~CRS! ⁄ @~R 2 1!~C!#, (3)
5 5.563 0.025 0.11
6 6.625 0.030 0.13
MOP 52~CRS! ⁄ @~R 2 1!~C 3 C !# (4)
M A
8 8.625 0.039 0.17
10 10.750 0.048 0.22
where:
12 12.750 0.057 0.26
14 14.000 0.063 0.28
σ = design stress, MPa,
S
16 16.000 0.072 0.40
MOP = maximum operating pressure, MPa,
18 18.000 0.081 0.54
D = averageoutsidediameter,seeTable2(mm)orTable
o
20 20.000 0.090 0.60
3 (in.), 22 22.000 0.099 0.66
24 24.000 0.108 0.72
t = minimum wall thickness, see Table 4 (mm) or Table
26 26.000 0.117 0.78
5 (in.),
28 28.000 0.126 0.98
R = standard dimension ratio (SDR) or dimension ratio
30 30.000 0.135 1.05
32 32.000 0.144 1.12
(DR),
34 34.000 0.153 1.19
MRS = minimum required strength, MPa,
36 36.000 0.162 1.26
CRS = categorized required strength, MPa, and
42 42.000 0.189 1.47
C = overall design coefficient – minimum of 2.0.
48 48.000 0.216 1.68
54 54.000 0.243 1.89
3.2.4.1 Discussion—MOPissometimesreferredtoasPNor
A
Values are consistent with ISO 14531-1.
nominal pressure.
3.2.5 minimum required strength (MRS), n—see ISO 12162
or PPI TR-4 for MRS definition.
3.2.5.1 Discussion—MRS is determined only at 20 °C and
3.2.6 nominal diameter, DN, adj—a designation for SI unit
50years.Foradesigntemperatureotherthan20°Coradesign
outside diameter controlled pipe sizes.
time other than 50 years, CRS is used in place of MRS, as
3.2.7 nominal pipe size, NPS, adj—a designation for inch-
discussed in 3.2.1.
pound unit outside diameter controlled pipe sizes.
3.2.8 overall design coeffıcient (C), n—a factor with a value
greater than 1, which takes into consideration material proper-
TABLE 2 Outside Diameters and Tolerances for DN Size PEX
ties (C ) and application service conditions (C ), as well as
Pipe M A
properties of the components of a piping system other than
Maximum of
Minimum outside Maximum outside
DN Size absolute out-of- those represented in the lower predictive limit. The minimum
diameter (mm) diameter (mm)
A
roundness (mm)
overall design coefficient (C ) for natural gas applications is
min
16 16.0 16.3 1.2
2.0, as specified in ISO 14531-1. The gas operator may add
20 20.0 20.3 1.2
additional application coefficients, depending on the
25 25.0 25.3 1.2
32 32.0 32.3 1.3 application, as shown below. See Appendix X1 for further
40 40.0 40.4 1.4
discussion on design coefficients.
50 50.0 50.4 1.4
63 63.0 63.4 1.5 C 5 C 3 C 51.25 31.6 3 C ,or
M A A1
75 75.0 75.5 1.6
C 52.0 3 C 3 C iftherearemultipleapplicationcoefficients
A1 A2
90 90.0 90.6 1.8
110 110.0 110.7 2.2 (5)
125 125.0 125.8 2.5
140 140.0 140.9 2.8 Design coefficients are sometimes referred to as reduction
160 160.0 161.0 3.2
factors.
180 180.0 181.1 3.6
200 200.0 201.2 4.0 3.2.8.1 application design coeffıcient (C ), n—a factor that
A
225 225.0 226.4 4.5
takes into account various aspects of the installation or the
250 250.0 251.5 5.0
applicationthattheplasticpipeisusedfor.Forgasdistribution,
280 280.0 281.7 9.8
315 315.0 316.9 11.1
C is 1.6, which results in the minimum overall design
A
355 355.0 357.2 12.5
coefficient of 2.0.Adding additional application coefficients is
400 400.0 402.4 14.0
lefttothedesignengineertoincorporateviaappropriatedesign
450 450.0 452.7 15.6
500 500.0 503.0 17.5 codes, national regulations or manufacturers
560 560.0 563.4 19.6
recommendations,andisdependentonlocationofthepipeline,
630 630.0 633.8 22.1
temperature, type of fluid being conveyed, and installation
710 710.0 716.4 24.9
800 800.0 817.2 28.0
method.
900 900.0 908.1 31.5
3.2.8.2 material design coeffıcient (C ), n—factorthattakes
1000 1000.0 1009.0 35.0 M
A intoaccountthepropertiesoftheplasticmaterial.ForPEX,the
Values are consistent with ISO 14531-1.
material coefficient (C ) is 1.25, as specified in ISO 12162.
M
F3534/F3534M−22
TABLE 4 Minimum Wall Thicknesses for DN Size PEX Pipe
A
All dimensions in mm
DN Size DR 6 DR 7.4 SDR 9 SDR 11 DR 13.6 DR 16.2 SDR 17
16 3.0 2.3 2.0 . . . .
20 3.4 3.0 2.3 2.0 . . .
25 4.2 3.5 3.0 2.3 2.0 . .
32 5.4 4.4 3.6 3.0 2.4 2.0 2.0
40 6.7 5.5 4.5 3.7 3.0 2.5 2.4
50 8.3 6.9 5.6 4.6 3.7 3.1 2.9
63 10.5 8.6 7.1 5.8 4.7 3.9 3.7
75 12.5 10.3 8.4 6.8 5.6 4.6 4.4
90 15.0 12.3 10.1 8.2 6.7 5.6 5.3
110 18.3 15.1 12.3 10.0 8.1 6.8 6.5
125 20.8 17.1 14.0 11.4 9.2 7.7 7.4
140 23.3 19.2 15.7 12.7 10.3 8.7 8.2
160 26.6 21.9 17.9 14.6 11.8 9.9 9.4
180 29.9 24.6 20.1 16.4 13.3 11.1 10.6
200 33.2 27.4 22.4 18.2 14.7 12.4 11.8
225 37.4 30.8 25.2 20.5 16.6 13.9 13.2
250 41.5 34.2 27.9 22.7 18.4 15.5 14.7
280 46.5 38.3 31.3 25.4 20.6 17.3 16.5
315 52.3 43.1 35.2 28.6 23.2 19.5 18.5
355 59.0 48.5 39.7 32.2 26.1 21.9 20.9
400 . 54.7 44.7 36.3 29.4 24.7 23.5
450 . 61.5 50.3 40.9 33.1 27.8 26.5
500 . . 55.8 45.4 36.8 30.9 29.4
560 . . 62.5 50.8 41.2 34.6 32.9
630 . . 70.3 57.2 46.3 38.9 37.0
710 . . 79.3 64.5 52.2 43.9 41.8
800 . . 89.3 72.6 58.8 49.4 47.0
900 . . . 81.7 66.2 56.6 52.9
1000 . . . 90.2 72.5 61.8 58.8
A
Small pipe diameters have minimum wall thicknesses values greater than the calculated value based on DR or SDR.
TABLE 5 Minimum Wall Thicknesses for NPS PEX Pipe
A
All dimensions in inches
DR DR
NPS DR 7.3 DR 8.3 SDR 9 SDR 11 SDR 17 SDR 21
13.5 15.5
3 0.479 0.422 0.389 0.318 0.259 0.226 0.206 0.167
4 0.616 0.542 0.500 0.409 0.333 0.290 0.265 0.214
5 0.762 0.670 0.618 0.506 0.412 0.359 0.327 0.265
6 0.908 0.798 0.736 0.602 0.491 0.427 0.390 0.315
8 1.182 1.039 0.958 0.784 0.639 0.556 0.507 0.411
10 1.473 1.295 1.194 0.977 0.796 0.694 0.632 0.512
12 1.747 1.536 1.417 1.159 0.944 0.823 0.750 0.607
14 1.918 1.687 1.556 1.273 1.037 0.903 0.824 0.667
16 2.192 1.928 1.778 1.455 1.185 1.032 0.941 0.762
18 2.466 2.169 2.000 1.636 1.333 1.161 1.059 0.857
20 . 2.409 2.222 1.818 1.481 1.290 1.176 0.952
22 . . 2.444 2.000 1.630 1.419 1.294 1.048
24 . . 2.667 2.182 1.778 1.548 1.412 1.143
26 . . . 2.364 1.926 1.677 1.529 1.238
28 . . . 2.545 2.074 1.806 1.647 1.333
30 . . . 2.727 2.222 1.935 1.765 1.429
32 . . . 2.909 2.370 2.065 1.882 1.524
34 . . . 3.091 2.519 2.194 2.000 1.619
36 . . . 3.273 2.667 2.323 2.118 1.714
42 . . . . . 2.710 2.471 2.000
48 . . . . . 3.097 2.824 2.286
54 . . . . . . 3.176 2.571
A
Small pipe diameters have minimum wall thicknesses values greater than the calculated value based on DR or SDR.
NOTE 2—The CRS for PEX pipe is only determined after the MRS is
4. Pipe Classification
established.
4.1 General—This specification covers two PEX ISO clas-
4.2 Operating Temperature Range—The determination of
sifications – PE-X 80 with an 8.0 MPa MRS and PE-X 100
the minimum operating temperature shall be in accordance
with a 10.0 MPa MRS. The maximum operating pressure
with6.10.Themaximumoperatingtemperatureisbasedonthe
(MOP)forPEXpipeisbasedontheMRSorCRSandshallbe
determined in accordance with the equations in 3.2.4. maximum temperature at which a CRS is determined by the
F3534/F3534M−22
pipe manufacturer or is listed in PPITR-4, but not greater than shallmeettheISO14531-1dispersionrequirementoflessthan
93 °C, as stated in 5.2. Operating temperatures higher than or equal to grade 3 when measured in accordance with ISO
93°C require special design considerations – consult with the 18553, or in accordance with an equivalentASTM test method
manufacturer. for carbon black dispersion, such as Test Method D5596.
5.5 Density—When determined in accordance with 7.5, the
5. Material Requirements
polyethylene compound prior to crosslinking shall have a
5.1 General—Crosslinkedpolyethylenematerialsshallmeet
minimum density of 0.926 g/cc.
all the requirements specified in Section 5. PEX materials are
5.6 Rework Material—PEX rework shall not be used in the
primarily defined by means of color, UV protection, and
manufacture of PEX pipe made in accordance to this specifi-
density.
cation.
5.2 Material Performance and MRS/CRS Requirements:
5.7 Chemical Resistance—The PEX material shall not in-
5.2.1 PEX pipe shall be made from polyethylene materials
crease in weight more than 0.5 % (1.0 % for toluene in
which have been crosslinked during the pipe manufacturing
methanol).Where the test specimen is a pipe ring, the material
process. The PEX compound shall meet the PE-X 80 or PE-X
shall not change more than 612 % in apparent tensile yield
100 ISO classification determined in accordance with ISO
strength when measured in accordance with 7.7.
9080 and ISO 12162 when tested in the form of pipe.The pipe
NOTE 6—This test is only an indication of what will happen as a result
shall also meet the performance requirements of Section 6.
of short-term exposure to these chemicals. For long-term results, addi-
5.2.2 To establish the maximum operating temperature, the
tional testing is required.
manufacturer shall determine the CRS at that temperature, as
discussed in Appendix X2. The PEX pipe shall have a 60 °C
6. Pipe Requirements
CRS at 50 years of at least 5.0 MPa.
6.1 Diameters and Tolerances:
NOTE 3—CRS times can range from 5 years to 100 years, and CRS
6.1.1 Outside Diameters—The outside diameters and toler-
temperatures can range from 0 °C to 93 °C.
ances shall be as shown in Table 2 for DN sizes or Table 3 for
5.3 Color:
NPS, when measured in accordance with 7.4 and 7.4.1.
5.3.1 PE compounds used to make black PEX pipe shall
6.1.2 Out-of Roundness—The out-of-roundness of pipe
contain well dispersed carbon black as a colorant.
made in accordance with this specification shall be less than or
5.3.2 PE compounds used to make yellow PEX pipe shall
equal to the values specified in Table 2 or Table 3 when
contain a yellow pigment as a colorant.
measuredinaccordancewithTestMethodD2122orISO3126.
5.3.3 Pipe made in accordance with this specification is
6.2 Wall Thickness and Tolerances—The wall thickness for
permitted to have co-extruded PEX colored stripes or PEX
pipe made in accordance with this specification shall be as
colored layers. These stripes or layers are on the OD of the
shown in Table 4 for DN sizes and in Table 5 for NPS, when
pipe. The PEX material used in the stripe or layer shall be the
measured in accordance with 7.4.2. The tolerance for all wall
sametypematerialasspecifiedin5.2forthePEXpipe.IfPEX
thicknesses is plus 12 %.
pipeistohavecoloredstripesorcoloredlayer,theMRStesting
NOTE 7—Small pipe diameters have minimum wall thicknesses values
specified in 5.2 shall be conducted on pipe samples with
greater than the calculated value based on DR or SDR.
colored stripes or colored layer.
6.3 Workmanship—The materials, procedure for mixing,
NOTE 4—Choice of yellow or black color for stripes or pipe is subject
and the pipe process for crosslinking shall result in a product
to agreement between manufacturer and purchaser.
with MRS values at 20 °C and 50 years as shown in Table 1,
5.4 UV Protection: when conditioned in accordance with 7.1 and determined in
5.4.1 Black pipe with or without yellow stripes shall be accordance with procedures no less restrictive than those of
stabilized and protected against deterioration from unprotected ISO 9080 or PPI TR-3. Table 6 provides design stress values
UV exposure for at least 10 years. Yellow pipe shall be for each MRS pipe material designation using the minimum
stabilized and protected against deterioration from unprotected overall design coefficient of 2.0 at 20 °C and 50 years. The
UV exposure for at least 3 years. design engineer shall also take into consideration the effect of
5.4.2 If the carbon black content in black pipe is less than
the environment on the overall design coefficient. The pipe
2.0 % or if the pipe is yellow, the pipe shall be weathered in shall be homogeneous throughout and free of visible cracks,
accordance with Test Method F2657, Practice D2565 or ISO
holes, foreign inclusions, or other defects.The pipe shall be as
14531-1,AnnexC.AfterPEXpipehasbeenweathered,itshall uniform as commercially practicable in color, opacity, density,
meet the thermal stability, 95 °C hydrostatic strength, and
and other physical properties.
elongation at break requirements of ISO 14531-1, Table 8.
NOTE 5—Generally, the acceleration factor for accelerated weathering
is between 3.75 to 4.4 times the number of test hours.
TABLE 6 PEX Pipe Design Stress at 20 °C
5.4.3 The UV requirement of 5.4.1 is not applicable if the
Design Stress for Natural Gas
contentofwell-dispersedcarbonblack,suchasN110orN550,
Material Designation
(MPa) (C = 2.0)
is greater than 2.0 % and less than 3.0 % as measured by Test
PEX 80 (MRS = 8 MPa) 4.0
MethodD1603orTestMethodD4218(seeISO14531-1,Table
PEX 100 (MRS = 10 MPa) 5.0
8).To demonstrate good carbon black dispersion the PEX pipe
F3534/F3534M−22
6.4 Hydrostatic Sustained Pressure Strength—Pipe samples minedinaccordancewith7.11shallbe17.4MPaforPEXpipe
tested in accordance with 7.6 shall not fail as defined in Test with an MRS of 8 MPa or 20.0 MPa for PEX pipe with an
Method D1598. MRS of 10 MPa.
6.4.1 The test pressure (P) is based on the following
6.9 Bent Pipe Hydrostatic Sustained Pressure Strength:
equation:
6.9.1 General—PEX pipe, up to and including DN 25, shall
P 52S ⁄ D ⁄ t 2 1 (6)
~ !
o
meet the requirements of 6.9.2.
where:
NOTE 8—PEX pipe larger than DN 25 is typically installed for main
P = test pressure, MPa, distribution lines and is installed in straight runs. Fittings are used when
a change in direction of 90° or greater and a bend radius of <6 times the
S = hoop stress in accordance with Table 7,
outside diameter is needed. The test procedures in 6.9.2 are intended to
D = outsidediameterinaccordancewithTable2orTable3,
o
evaluate PEX pipe installed in tight bend applications as discussed in
and
X3.2.5. This application applies to pipe up to and including DN 25
t = minimumwallthickness,inaccordancewithTable4or
nominal diameter only.
Table 5.
6.9.2 Hot-bent pipe, with a bend radius of 2.5 times the
6.5 Minimum Hydrostatic Burst Pressure (Quick Burst)—
outside diameter, and cold-bent pipe, with a bend radius of 6
The pipe shall fail in a ductile manner when tested in
times the outside diameter, and each having a continuous bend
accordance with 7.10. For pipe sizes above 4 in. [110 mm]
inducing not less than a 90° angle, shall meet the minimum
nominaldiameter,thetestinglabshallbeallowedtoreplacethe
hydrostatic sustained pressure strength requirements for 95 °C
quickbursttestbytheapparentringtensilestrengthtestin6.8.
as shown in Table 7 when tested in accordance with 7.6. The
6.6 Degree of Crosslinking: bend length and bend angle is maintained throughout the
6.6.1 When tested in accordance with 7.8, the degree of testing period by rigid supports immediately outside the bend.
crosslinking for PEX pipe shall meet the following specified
6.10 Pipe Minimum Operating Temperature:
requirements before installation. The minimum percentage
6.10.1 The minimum operating temperature for pipe shall
crosslinking value shall be 65 % for PEX compounds cross
...