ASTM F2818-10(2023)
(Specification)Standard Specification for Specification for Crosslinked Polyethylene (PEX) Material Gas Pressure Pipe and Tubing
Standard Specification for Specification for Crosslinked Polyethylene (PEX) Material Gas Pressure Pipe and Tubing
ABSTRACT
This specification covers requirements and test methods for material dimensions and tolerances, hydrostatic burst strength, chemical resistance, and impact resistance of PEX pipe and tubing for use in fuel gas mains and services for direct burial applications. Requirements cover workmanship, pipe and tubing dimensions and tolerances, chemical resistance, sustained pressure, elevated temperature, thermal stability, slow crack growth resistance, minimum hydrostatic burst pressure/apparent tensile strength (quick burst), apparent tensile strength at yield, squeeze-off, thermal stability, slow crack growth resistance, and joints.
SCOPE
1.1 This specification covers requirements and test methods for material dimensions and tolerances, hydrostatic burst strength, chemical resistance, and impact resistance of PEX pipe and tubing for use in fuel gas mains and services for direct burial applications.
1.2 The text of this specification references notes and footnotes provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.
1.5 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.
General Information
Relations
Standards Content (Sample)
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: F2818 − 10 (Reapproved 2023) An American National Standard
Standard Specification for
Specification for Crosslinked Polyethylene (PEX) Material
Gas Pressure Pipe and Tubing
This standard is issued under the fixed designation F2818; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope D792 Test Methods for Density and Specific Gravity (Rela-
tive Density) of Plastics by Displacement
1.1 This specification covers requirements and test methods
D1505 Test Method for Density of Plastics by the Density-
for material dimensions and tolerances, hydrostatic burst
Gradient Technique
strength, chemical resistance, and impact resistance of PEX
D1598 Test Method for Time-to-Failure of Plastic Pipe
pipe and tubing for use in fuel gas mains and services for direct
Under Constant Internal Pressure
burial applications.
D1599 Test Method for Resistance to Short-Time Hydraulic
1.2 The text of this specification references notes and
Pressure of Plastic Pipe, Tubing, and Fittings
footnotes provide explanatory material. These notes and foot-
D1600 Terminology for Abbreviated Terms Relating to Plas-
notes (excluding those in tables and figures) shall not be
tics
considered as requirements of the specification. 3
D1898 Practice for Sampling of Plastics (Withdrawn 1998)
D2122 Test Method for Determining Dimensions of Ther-
1.3 The values stated in inch-pound units are to be regarded
as standard. The values given in parentheses are mathematical moplastic Pipe and Fittings
D2290 Test Method for Apparent Hoop Tensile Strength of
conversions to SI units that are provided for information only
and are not considered standard. Plastic or Reinforced Plastic Pipe
D2513 Specification for Polyethylene (PE) Gas Pressure
1.4 This standard does not purport to address all of the
Pipe, Tubing, and Fittings
safety concerns, if any, associated with its use. It is the
D2765 Test Methods for Determination of Gel Content and
responsibility of the user of this standard to establish appro-
Swell Ratio of Crosslinked Ethylene Plastics
priate safety, health, and environmental practices and deter-
D2837 Test Method for Obtaining Hydrostatic Design Basis
mine the applicability of regulatory limitations prior to use.
for Thermoplastic Pipe Materials or Pressure Design Basis
1.5 This international standard was developed in accor-
for Thermoplastic Pipe Products
dance with internationally recognized principles on standard-
D3350 Specification for Polyethylene Plastics Pipe and Fit-
ization established in the Decision on Principles for the
tings Materials
Development of International Standards, Guides and Recom-
D4883 Test Method for Density of Polyethylene by the
mendations issued by the World Trade Organization Technical
Ultrasound Technique
Barriers to Trade (TBT) Committee.
F412 Terminology Relating to Plastic Piping Systems
F1473 Test Method for Notch Tensile Test to Measure the
2. Referenced Documents
Resistance to Slow Crack Growth of Polyethylene Pipes
2.1 ASTM Standards:
and Resins
D543 Practices for Evaluating the Resistance of Plastics to
F1563 Specification for Tools to Squeeze-off Polyethylene
Chemical Reagents
(PE) Gas Pipe or Tubing
D618 Practice for Conditioning Plastics for Testing
F1041 Guide for Squeeze-Off of Polyolefin Gas Pressure
D638 Test Method for Tensile Properties of Plastics
Pipe and Tubing
2.2 Other Standards and Publications:
B31.8 Gas Transmission and Distribution Piping Systems
This specification is under the jurisdiction of ASTM Committee F17 on Plastic
PPI-TR3 Policies and Procedures for Developing Hydro-
Piping Systems and is the direct responsibility of Subcommittee F17.60 on Gas.
static Design Basis (HDB), Pressure Design Basis (PDB),
Current edition approved July 1, 2023. Published July 2023. Originally published
in 2010. Last previous edition approved in 2019 as F2818 – 10 (2019).
DOI:10.1520/F2818-10R23.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or The last approved version of this historical standard is referenced on
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM www.astm.org.
Standards volume information, refer to the standard’s Document Summary page on Available from American National Standards Institute (ANSI), 25 W. 43rd St.,
the ASTM website. 4th Floor, New York, NY 10036, http://www.ansi.org.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2818 − 10 (2023)
Strength Design Basis (SDB), and Minimum Required 4.3 Density—The PEX pipe material shall have a minimum
Strength (MRS) Ratings for Thermoplastic Piping Mate- density of 0.926 g/cc when determined in accordance with Test
rials or Pipe Methods D1505, D792, or D4883.
CFR Part 192 Transportation of Natural and Other Gas by
4.4 Outdoor Storage Stability—PE materials shall be Code
Pipeline: Minimum Federal Safety Standards
C or E as defined in Specification D3350. Code C material
shall contain 2 to 3 percent well dispersed carbon black, and
3. Terminology
due to the absorptive properties of the carbon black, is
3.1 Definitions—Are in accordance with Terminology F412,
considered to be stabilized against deterioration from unpro-
and abbreviations are in accordance with Terminology D1600,
tected exposure to UV for at least 10 years. Code E material
unless otherwise specified.
shall be stabilized and protected against deterioration from
unprotected UV exposure for not less than 3 years.
3.2 The gas industry terminology used in this specification
is in accordance with ANSI B31.8 or 49 CFR Part 192, unless
4.5 Rework Material—PEX rework shall not be used in the
otherwise indicated.
manufacture of PEX pipes made in accordance to this specifi-
cation.
3.3 The term pipe used herein refers to both pipe and tubing
unless specifically stated otherwise.
5. Requirements
3.4 Definitions of Terms Specific to This Standard:
5.1 General—Pipe shall be supplied in either coils or
3.4.1 toe-in—a small reduction of the outside diameter at
straight lengths. Any pipe supplied in coils must meet the same
the cut end of a length of thermoplastic pipe.
requirements before and after coiling. The requirements apply
to pipe after crosslinking.
4. Ordering Information
5.2 Workmanship—The pipe and fittings shall be homoge-
4.1 General—The plastic used to make pipe and fittings
neous throughout and free of visible cracks, holes, foreign
shall have a Plastics Pipe Institute (PPI) long-term hydrostatic
inclusion, blisters, and dents, or other injurious defects. The
design stress and hydrostatic design basis rating. PEX pipe are
pipe and fittings shall be as uniform as commercially practi-
primarily defined by means of three criteria, namely, (1)
cable in color, opacity, density, and other physical properties.
nominal density, (2) degree of crosslinking, and (3) long-term
strength tests. There is a strong correlation between nominal
5.3 Pipe and Tubing Dimensions and Tolerances:
density and results of short-term strength tests.
5.3.1 Dimension—The dimensions shall be specified by
wall thickness and outside diameter.
4.2 Basic Materials—PEX pipe shall be made from poly-
5.3.1.1 Diameters—The outside diameter shall meet the
ethylene compounds which have been crosslinked by
requirements given in Table 1 or Table 2 when measured in
peroxides, Azo compounds, or silane compounds in extrusion,
accordance with 6.5.
or by electron beam after extrusion, or by other means such
5.3.1.2 Toe-In—When measured in accordance with 6.5.1.1,
that the pipe meets the performance requirements of this
the outside diameter at the cut end of the pipe shall not be more
specification. The materials, procedure for mixing, and the
than 1.5 % smaller than the undistorted outside diameter.
process for crosslinking shall result in a product with minimum
Measurement of the undistorted outside diameter shall be made
recommended long term hydrostatic design basis (HDB) equal
no closer than 1.5 pipe diameters or 11.8 in. (300 mm),
to or greater than 1250 psi at 73.4°F (23°C) (PEX XX06) and
whichever distance is less, from the cut end of the pipe.
800 psi at 180 °F (82.2 °C) when determined in accordance
Undistorted outside diameter shall meet the requirements of
with PPI-TR3 and Test Method D2837.
Table 1 or Table 2.
5.3.1.3 Wall Thickness—The wall thickness shall be as
specified in Table 2 or Table 3 when measured in accordance
Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825,
with 6.5.1.2. The minimum wall thickness at any point of
Irving, TX 75062, http://www.plasticpipe.org.
Available from U.S. Government Printing Office, Superintendent of measurement shall be not less than the minimum wall thickness
Documents, 732 N. Capitol St., NW, Washington, DC 20401-0001, http://
specified in Table 2 or Table 3.
www.access.gpo.gov.
TABLE 1 Outside Diameters and Tolerances for Plastic Pipe, in. (mm)
Maximum Out of Roundness
Iron Pipe Size SDR 17
Outside Diameter Tolerance
(IPS) SDR 13.5
SDR 11
⁄2 0.840 (21.3) ±0.004 (±0.102) 0.016(0.406)
⁄4 1.050 (26.7) ±0.004 (±0.102) 0.02(0.508)
1 1.315 (33.4) ±0.005 (±0.127) 0.02(0.508)
1 ⁄4 1.660 (42.1) ±0.005 (±0.127) 0.024(0.61)
1 ⁄2 1.900 (48.3) ±0.006 (±0.152) 0.024(0.61)
2 2.375 (60.3) ±0.006 (±0.152) 0.024(0.61)
3 3.500 (88.9) ±0.008 (±0.203) 0.03(0.762)
4 4.500 (114.3) ±0.009 (±0.229) 0.03(0.762)
6 6.625 (168.3) ±0.011 (±0.279) 0.07(1.778)
F2818 − 10 (2023)
TABLE 2 Plastic Tubing-Diameters, Wall Thicknesses, and Tolerances, in. (mm)
Copper Tubing Outside Tolerance Minimum Wall Thickness
Size Diameter Wall Thickness Tolerance
(CTS)
⁄4 0.375 (9.52) ±0.004 (±0.10) 0.062 (1.58) +0.006 (+0.15)
⁄8 0.500 (12.7) ±0.004 (±0.10) 0.062 (1.58) +0.006 (+0.15)
⁄2 0.625 (15.9) ±0.004 (±0.10) 0.062 (1.58) +0.006 (+0.15)
⁄2 0.625 (15.9) ±0.004 (±0.10) 0.090 (2.27) +0.009 (+0.23)
⁄2 0.625 (15.9) ±0.004 (±0.10) 0.104 (2.64) +0.010 (+0.25)
⁄4 0.875 (22.2) ±0.004 (±0.10) 0.062 (1.58) +0.006 (+0.15)
⁄4 0.875 (22.2) ±0.004 (±0.10) 0.077 (1.95) +0.008 (+0.20)
⁄4 0.875 (22.2) ±0.004 (±0.10) 0.090 (2.27) +0.009 (+0.23)
1 1.125 (28.6) ±0.005 (±0.13) 0.062 (1.58) +0.007 (+0.18)
1 1.125 (28.6) ±0.005 (±0.13) 0.090 (2.27) +0.011 (+0.28)
1 1.125 (28.6) ±0.005 (±0.13) 0.099 (2.51) +0.012 (+0.31)
1 1.125 (28.6) ±0.005 (±0.13) 0.101 (2.56) +0.012 (+0.31)
1 1.125 (28.6) ±0.005 (±0.13) 0.121 (3.07) +0.015 (+0.38)
1 ⁄4 1.375 (34.9) ±0.005 (±0.13) 0.062 (1.58) +0.007 (+0.18)
1 ⁄4 1.375 (34.9) ±0.005 (±0.13) 0.090 (2.27) +0.011 (+0.28)
1 ⁄4 1.375 (34.9) ±0.005 (±0.13) 0.121 (3.07) +0.015 (+0.38)
1 ⁄4 1.875 (47.6) ±0.006 (±0.15) 0.062 (1.58) +0.007 (+0.18)
additional testing is required.
5.3.1.4 Wall Thickness Eccentricity Range—The wall thick-
ness eccentricity range shall be within 12 % when measured in
5.5 Sustained Pressure 73 °F (23 °C)—The pipe shall not
accordance with 6.5.1.3.
fail in less than 1000 h when tested in accordance with Test
5.3.1.5 Length—The pipe shall be supplied in straight
Method D1598. For PEX XX06 material, the stress shall be
lengths or coils as agreed upon between the manufacturer and
1320 psi (9.1 MPa), for PEX XX08 material, the stress shall be
the purchaser. The length shall not be less than the minimum
1600 psi (11.03 MPa).
length agreed upon when corrected to 73 °F (23 °C).
5.3.1.6 When sizes other than those listed in Table 1, Table 5.6 Elevated Temperature 203 °F (95 °C)—PEX piping ma-
2, or Table 3 are used, tolerances shall be: for outside diameter, terials intended for use at temperatures above 100 °F (38 °C)
use same tolerance of next smaller size; for wall thickness, use shall have the PPI hydrostatic design basis (HDB) determined
same tolerance percentage as shown in the tables.
at the specific temperature in accordance with Test Method
5.3.2 Degree of Crosslinking—The degree of crosslinking D2837.
for PEX pipe shall be within the range from 65 % to 89 %
NOTE 3—Many design factors for elevated temperature service cannot
inclusive. Depending on the process used, the following
be covered in this specification. Users should consult applicable codes for
minimum percentage crosslinking values shall be achieved:
limitations on pertinent maximum temperatures.
70 % by peroxides, 65 % by Azo compounds, 65 % by electron
NOTE 4—In the absence of an HDB established at the specified
beam, or 65 % by silane compound. The degree of crosslinking
temperature, the HDB of a higher temperature may be used in determining
on a pipe sample is obtained as follows: a design pressure rating at the specified temperature by arithmetic
interpolation.
5.3.2.1 Place a pipe sample in a lathe with automatic
feeding. Shave a strip that consists of the full wall thickness.
5.7 Minimum Hydrostatic Burst Pressure/Apparent Tensile
The strip thickness shall be approximately 0.004 in. (0.1 mm)
Strength (Quick Burst)—The pipe shall fail in a ductile manner
which is obtained by setting the lathe feeding accordingly.
when tested in accordance with Test Method D1599. For pipe
5.3.2.2 Test the specimens in accordance with Test Method
sizes above 4-in. nominal diameter, the testing lab shall be
D2765, Method B, with the only deviation: test specimen
allowed to replace the quick burst test (Test Method D1599) by
preparation. For the purpose of this specification, degree of
the apparent ring tensile strength test (Test Method D2290).
crosslinking (V) is defined as 100 % minus extract percent
The minimum apparent tensile strength at yield when deter-
equals V.
mined in accordance with 6.7 shall be 2520 psi (17.4 MPa).
NOTE 1—Test Method D2765, Method A may be used in lieu of Method
5.8 Apparent Tensile Strength at Yield—When tested in
B. Method A gives more accurate and reproducible values but require a
accordance to 6.8, the PEX pipe shall demonstrate a minimum
special grinder for sample preparation.
of 2600 psi for PEX XX06 materials and 3000 psi for PEX
5.4 Chemical Resistance—The pipe and fittings shall not
XX08 materials.
increase in weight more than 0.5 % (1.0 % for toluene in
methanol). Where the test specimen is a pipe ring, the material
5.9 Squeeze-Off—This requirement is limited to pipe sizes,
shall not change more than 612 % in apparent tensile yield
wall thicknesses, squeeze procedures, and conditions deemed
strength when measured in accordance with 6.9. Where the test
suitable f
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