ASTM F2968/F2968M-21

This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: F2968/F2968M − 20a F2968/F2968M − 21 An American National Standard
Standard Specification for
Crosslinked Polyethylene (PEX) Pipe for Gas Distribution
Applications
This standard is issued under the fixed designation F2968/F2968M; 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*
1.1 This specification covers outside diameter controlled, metric-sized and inch-sized black or yellow crosslinked polyethylene
(PEX) pipe, made in pipe dimension ratios ranging from 6 to 17, and pressure rated for gas distribution. Included are requirements
and test methods for material, workmanship, dimensions, burst pressure, hydrostatic sustained pressure, stabilizer functionality,
bent-pipe hydrostatic pressure, degree of crosslinking, chemical resistance, minimum operating temperature and squeeze-off.
Requirements for pipe markings are also given. The pipe covered by this specification is intended for buried gas distribution and
gas transmission pressure piping applications.
1.2 This specification also includes requirements for joints made between PEX pipe and polyethylene electrofusion fittings (such
as(specified in Specification F1055F3373). Fittings to be used with PEX pipe manufactured to this specification are in Specification
F2829F2829/F2829M. Installation considerations are in X3.2.
NOTE 1—Inch-sized fittings should not be used for metric-sized pipe, and metric-sized fittings should not be used for inch-sized pipe.
1.3 The text of this specification references notes, footnotes, and appendixes, which provide explanatory material. These notes and
footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification.
1.4 Units—The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in
each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used
independently of the other, and values from the two systems shall not be combined.
1.5 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 and health practices and determine the applicability of regulatory
limitations prior to use.
1.6 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.
This specification is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.60 on Gas.
Current edition approved April 1, 2020May 1, 2021. Published April 2020May 2021. Originally approved in 2014. Last previous edition approved in 2020 as
D2968/D2968M–20.–20a. DOI: 10.1520/F2968/F2968M–20A.10.1520/F2968_F2968M–21.
*A Summary of Changes section appears at the end of this standard
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F2968/F2968M − 21
2. Referenced Documents
2.1 ASTM Standards:
D543 Practices for Evaluating the Resistance of Plastics to Chemical Reagents
D618 Practice for Conditioning Plastics for Testing
D792 Test Methods for Density and Specific Gravity (Relative Density) of Plastics by Displacement
D1505 Test Method for Density of Plastics by the Density-Gradient Technique
D1598 Test Method for Time-to-Failure of Plastic Pipe Under Constant Internal Pressure
D1599 Test Method for Resistance to Short-Time Hydraulic Pressure of Plastic Pipe, Tubing, and Fittings
D1600 Terminology for Abbreviated Terms Relating to Plastics
D1603 Test Method for Carbon Black Content in Olefin Plastics
D2122 Test Method for Determining Dimensions of Thermoplastic Pipe and Fittings
D2290 Test Method for Apparent Hoop Tensile Strength of Plastic or Reinforced Plastic Pipe
D2565 Practice for Xenon-Arc Exposure of Plastics Intended for Outdoor Applications
D2765 Test Methods for Determination of Gel Content and Swell Ratio of Crosslinked Ethylene Plastics
D2837 Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis for
Thermoplastic Pipe Products
D4218 Test Method for Determination of Carbon Black Content in Polyethylene Compounds by the Muffle-Furnace Technique
D5596 Test Method for Microscopic Evaluation of the Dispersion of Carbon Black in Polyolefin Geosynthetics
F412 Terminology Relating to Plastic Piping Systems
F876 Specification for Crosslinked Polyethylene (PEX) Tubing
F1041 Guide for Squeeze-Off of Polyolefin Gas Pressure Pipe and Tubing
F1055 Specification for Electrofusion Type Polyethylene Fittings for Outside Diameter Controlled Polyethylene and Crosslinked
Polyethylene (PEX) Pipe and Tubing
F1563 Specification for Tools to Squeeze-off Polyethylene (PE) Gas Pipe or Tubing
F1948 Specification for Metallic Mechanical Fittings for Use on Outside Diameter Controlled Thermoplastic Gas Distribution
Pipe and Tubing
F2657 Test Method for Outdoor Weathering Exposure of Crosslinked Polyethylene (PEX) Tubing
F2829F2829/F2829M Specification for Metric- and Inch-Sized Fittings for Crosslinked Polyethylene (PEX) Pipe
F2897 Specification for Tracking and Traceability Encoding System of Natural Gas Distribution Components (Pipe, Tubing,
Fittings, Valves, and Appurtenances)
F3373 Specification for Polyethylene (PE) Electrofusion Fittings for Outside Diameter Controlled Crosslinked Polyethylene
(PEX) Pipe
2.2 Federal Standard:
FED-STD-123 Marking for Shipment (Civil Agencies)
2.3 Military Standard:
MIL-STD-129 Marking for Shipment and Storage
2.4 ISO Standards:
ISO 1167 Thermoplastics pipes, fittings and assemblies for the conveyance of fluids — Determination of the resistance to
internal pressure — Part 1: General method
ISO 13477 Thermoplastics pipes for the conveyance of fluids — Determination of resistance to rapid crack propagation (RCP)
— Small-scale steady-state test (S4 test)
ISO 14531-1 Plastics pipes and fittings — Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels
— Metric series — Specifications — Part 1: Pipes
ISO 14531-2 Plastics pipes and fittings — Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels
— Metric series — Specifications — Part 2: Fittings for heat-fusion jointing
ISO 14531-3 Plastics pipes and fittings — Crosslinked polyethylene (PE-X) pipe systems for the conveyance of gaseous fuels
— Metric series — Specifications — Part 3: Fittings for mechanical jointing (including PE-X/metal transitions)
ISO 18553 Method for the assessment of the degree of pigment or carbon black dispersion in polyolefin pipes, fittings and
compounds.
2.5 PPI Standards:
PPI TR-3 Policies and Procedures for Developing Hydrostatic Design Basis (HDB), Pressure Design Basis (PDB), Strength
Design Basis (SDB), and Minimum Required Strength (MRS) Ratings for Thermoplastic Piping Materials or Pipe
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
DLA Document Services Building 4/D 700 Robbins Avenue Philadelphia, PA 19111-5094 http://quicksearch.dla.mil/
Available from International Organization for Standardization (ISO), 1, ch. de la Voie-Creuse, CP 56, CH-1211 Geneva 20, Switzerland, http://www.iso.org.
Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825, Irving, TX 75062, http://www.plasticpipe.org.
F2968/F2968M − 21
PPI TR-4 PPI Listing of Hydrostatic Design Basis (HDB), Strength Design Basis (SDB), Pressure Design Basis (PDB) and
Minimum Required Strength (MRS) Ratings for Thermoplastic Piping Materials or Pipe
PEX Pipe Design Manual for Water, Oil, Gas & Industrial Applications
3. Terminology
3.1 Definitions—Definitions are in accordance with Terminology F412, and abbreviations are in accordance with Terminology
D1600, unless otherwise specified. The abbreviation for crosslinked polyethylene is PEX. Plastic pipe denotes a particular diameter
schedule of plastic pipe that is outside diameter controlled.
3.2 Definitions of Terms Specific to This Standard:
3.2.1 crosslinked polyethylene, n—a polyethylene material that has undergone a change in molecular structure using a chemical
or a physical process whereby the polymer chains are chemically linked.
3.2.2 PEX pipe material designation code—The PEX pipe material designation code shall consist of the abbreviation for
crosslinked polyethylene (PEX) followed by four Arabic digits as shown in Table 1, and as defined in Terminology F412 for PEX
pipe materials.
4. Pipe Classification
4.1 General—This specification covers PEX pipe that is pressure rated based on HDB at 73 °F [23 °C] and 200 °F [93 °C].
Pressure ratings for temperatures between 73 °F [23 °C] and 200 °F [93 °C] are determined by temperature interpolation in
accordance with PPI TR-3.
4.2 Classification—PEX pipes are classified by their PEX pipe material designation codes as shown in Table 1.
4.3 Operating Temperature Range—The minimum operating temperature shall be in accordance with 6.13. The maximum
temperature for continuous operation shall be based on the highest temperature HDB in accordance with 5.2 and Table 1. The
maximum temperature for intermittent operation shall require special design considerations and consultation with the pipe
manufacturer and shall be consistent with the PPI “PEX Pipe Design Manual for Water, Oil, Gas & Industrial Applications”.
5. Materials
5.1 General—PEX pipes, meeting the requirements of this specification, are defined by means of (1) degree of crosslinking per
6.7, and (2) long-term strength tests per Test Method D2837 to determine HDB per Table 1. The HDB is a property of the PEX
compound, which is used to make the PEX pipe.
5.2 Basic Materials—PEX pipe and fittings shall be made from PE compounds, which have been crosslinked by peroxides, azo
compounds, or silane compounds in extrusion, or by electron beam after extrusion, such that the pipe meets the performance
requirements of Section 6. The materials, procedure for mixing, and the process for crosslinking shall result in a product with
Hydrostatic Design Basis ratings equal to or better than those shown in Table 1, when determined in accordance with procedures
no less restrictive than those of Test Method D2837, and the PEX material shall have a Plastics Pipe Institute (PPI) long-term
hydrostatic design stress and hydrostatic design basis rating per PPI TR-3. See Appendix X1 for additional information on PPI
hydrostatic stress ratings.
5.3 Pipe Material Designation Code—The PEX material meeting the requirements of this specification shall be designated PEX
0006, PEX 0008 or PEX 0009.
NOTE 2—The first two digits in the pipe material designation code are for chlorine resistance and UV resistance. A “0” indicates “not tested”. If either
TABLE 1 PEX Pipe Material Designation Codes
PEX Pipe Material 73 ºF [23 ºC] HDB 200 ºF [93 ºC] HDB
Designation Code Psi [MPa] Psi [MPa]
PEX 0006 1250 [8.62] 630 [4.34]
PEX 0008 1600 [11.03] 630 [4.34]
PEX 0009 1800 [12.41] 630 [4.34]
F2968/F2968M − 21
of these properties has been tested, then the “0” is replaced by the appropriate digit.
5.4 Density—When determined in accordance with 7.5, the PE base resin used for PEX pipe, without carbon black, used for PEX
pipe shall have a minimum average density of 0.926 g/cm .
5.5 Color:
5.5.1 PE compounds used to make black PEX pipe shall contain well dispersed carbon black as a colorant.
5.5.2 PE compounds used to make yellow PEX pipe shall contain a yellow pigment as a colorant.
5.6 UV Protection:
5.6.1 Black pipe with or without yellow stripes shall be stabilized and protected against deterioration from unprotected UV
exposure for not less than 10 years. Yellow pipe shall be stabilized and protected against deterioration from unprotected UV
exposure for not less than 3 years.
5.6.2 If the carbon black content is less than 2.0 %, the pipe shall be tested in accordance with Test Method F2657, Practice D2565
or ISO 14531-1 Annex C. After PEX pipe has been weathered, it shall meet the thermal stability, 95 °C hydrostatic strength (for
stress values, use 536 psi (3.7 MPa) for PEX 0006, 681 psi (4.7 MPa) for PEX 0008, or 768 psi (5.3 MPa) for PEX 0009), and
elongation at break requirements of ISO 14531-1, Table 8.
5.6.3 If the carbon black content is greater than 2.0 % and less than 3.0 % as measured by Test Method D1603 or Test Method
D4218, the UV exposure time requirement of 5.6.2 is not applicable This is consistent with ISO 14531-1, Table 8. The carbon black
shall be well dispersed, and have the correct type (furnace) and particle size (40 nm or less), such as N550. To demonstrate good
carbon black dispersion the PEX pipe shall meet the ISO 14531-1 dispersion requirement of less than or equal to grade 3 when
measured in accordance with ISO 18553, or in accordance with an equivalent ASTM test method for carbon black dispersion, such
as Test Method D5596.
5.7 Rework Material—PEX rework shall not be used in the manufacture of PEX pipes and fittings made in accordance to this
specification.
5.8 Chemical Resistance—The PEX material shall not increase in weight more than 0.5 % (1.0 % for toluene in methanol). Where
the test specimen is a pipe ring, the material shall not change more than 612 % in apparent tensile yield strength when measured
in accordance with 7.11.
NOTE 3—This test is only an indication of what will happen as a result of short-term exposure to these chemicals. For long-term results, additional testing
is required.
6. Requirements
6.1 Workmanship—The pipe shall be homogeneous throughout and free of visible cracks, holes, foreign inclusions, or other
defects. The pipe shall be as uniform as commercially practicable in color, opacity, density, and other physical properties.
6.2 Out-of Roundness—The maximum out-of roundness requirements shown in Table 2 and Table 3 for pipe apply to the average
measured diameter in accordance with 7.4.1.
6.3 Dimensions and Tolerances:
6.3.1 Outside Diameters—The outside diameters and tolerances shall be as shown in Table 2 or Table 3, when measured in
accordance with 7.4 and 7.4.1.
6.3.2 Wall Thickness—The wall thickness and tolerances shall be as shown in Table 4 or Table 5, when measured in accordance
with 7.4 and 7.4.2.
6.4 Sustained Pressure 73°F [23°C]—73 °F [23 °C]—The PEX pipe shall not fail in less than 1000 h when tested in accordance
F2968/F2968M − 21
TABLE 2 Metric-sized Outside Diameters and Tolerances for PEX Pipe
Pipe Size Average Outside Diameter Tolerances for Average Diameter Out-of-Roundness
mm mm mm mm
16 16.15 ±0.15 1.2
20 20.15 ±0.15 1.2
25 25.15 ±0.15 1.2
32 32.15 ±0.15 1.3
40 40.20 ±0.20 1.4
50 50.20 ±0.20 1.4
63 63.20 ±0.20 1.5
75 75.25 ±0.25 1.6
90 90.30 ±0.30 1.8
110 110.35 ±0.35 2.2
125 125.40 ±0.40 2.5
140 140.45 ±0.45 2.8
160 160.50 ±0.50 3.2
180 180.55 ±0.55 3.6
200 200.60 ±0.60 4.0
225 225.70 ±0.70 4.5
250 250.75 ±0.75 5.0
280 280.85 ±0.85 9.8
315 315.95 ±0.95 11.1
355 356.10 ±1.10 12.5
400 410.20 ±1.20 14.0
450 451.35 ±1.35 15.6
500 501.50 ±1.50 17.5
560 561.70 ±1.70 19.6
630 631.90 ±1.90 22.1
710 713.20 ±3.20 24.8
800 813.00 ±3.60 28.0
900 904.05 ±4.05 31.5
1000 1004.50 ±4.50 35.0
TABLE 3 Inch-sized Outside Diameters and Tolerances for PEX
Pipe
Pipe Size Outside Diameter Tolerances for Outside
Diameter (±)
in. in. in.
3 3.500 0.016
4 4.500 0.020
5 5.563 0.025
6 6.625 0.030
8 8.625 0.039
10 10.750 0.048
12 12.750 0.057
14 14.000 0.063
16 16.000 0.072
18 18.000 0.081
20 20.000 0.090
22 22.000 0.099
24 24.000 0.108
26 26.000 0.117
28 28.000 0.126
30 30.000 0.135
32 32.000 0.144
34 34.000 0.153
36 36.000 0.162
42 42.000 0.189
48 48.000 0.216
54 54.000 0.243
with 7.6. For PEX 0006 the stress shall be 1320 psi [9.1 MPa], for PEX 0008 the stress shall be 1650 psi [11.3 MPa], and for PEX
0009 the stress shall be 2050 psi [14.1 MPa]. Piping intended for use at temperatures of 100 °F [38 °C] and higher shall be tested
at both 73 °F [23 °C] and the maximum design temperature. The test fiber stress shall be 90 % of the HDB.
6.5 Minimum Hydrostatic Burst Pressure (Quick Burst)—The pipe shall fail in a ductile manner when tested in accordance with
7.7. For pipe sizes above 4 in [110 mm] nominal diameter, the testing lab shall be allowed to replace the quick burst test by the
apparent ring tensile strength test in 6.6.
F2968/F2968M − 21
TABLE 4 Metric-sized Wall Thickness and Tolerances for PEX Plastic Pipe
Minimum Wall Thickness (t), mm (tolerance is plus 12%)
Minimum Wall Thickness (t), mm (tolerance is plus 12 %)
Pipe Size [mm] DR 6 DR 7.4 DR 9 DR 11 DR 13.6 DR 16.2 DR 17 DR 21
16 3.0 2.3 2.0 . . . . .
20 3.4 3.0 2.3 2.0 . . . .
25 5.4 3.5 3.0 2.3 2.0 . . .
32 5.4 4.4 3.6 3.0 2.4 2.0 2.0 2.3
40 6.7 5.5 4.5 3.7 3.0 2.5 2.4 2.8
50 8.3 6.9 5.6 4.6 3.7 3.1 3.0 3.4
63 10.5 8.6 7.1 5.8 4.7 3.9 3.8 4.3
75 12.5 10.3 8.4 6.8 5.6 4.6 4.5 5.1
90 15.0 12.3 10.1 8.2 6.7 5.6 5.4 6.1
110 18.3 15.1 12.3 10.0 8.1 7.7 6.6 7.4
125 20.8 17.1 14.0 11.4 9.2 7.7 7.4 8.3
140 23.3 19.2 15.7 12.7 10.3 8.7 8.3 9.3
160 26.6 21.9 17.9 14.6 11.8 9.9 9.5 10.6
180 29.9 24.6 20.1 16.4 13.3 11.1 10.7 11.9
200 33.2 27.4 22.4 18.2 14.7 12.4 11.9 13.2
225 37.4 30.8 25.2 20.5 16.6 13.9 13.4 14.9
250 41.5 34.2 27.9 22.7 18.4 15.5 14.8 16.4
280 46.5 38.3 31.3 25.4 20.6 17.3 16.6 18.4
315 52.3 43.1 35.2 28.6 23.2 19.5 18.7 20.7
355 59.0 48.5 39.7 32.2 26.1 21.9 21.1 23.4
400 . 54.7 44.7 36.3 29.4 24.7 26.2 23.7
450 . 61.5 50.3 40.9 33.1 27.8 26.7 29.5
500 . . 55.8 45.4 36.8 30.9 29.7 32.8
560 . . 62.5 50.8 41.2 34.6 33.2 36.7
630 . . 70.3 57.2 46.3 38.9 37.4 41.3
710 . . 79.3 64.5 52.2 43.9 42.1 46.5
800 . . 89.3 72.6 58.8 49.4 47.4 52.3
900 . . . 81.7 66.2 56.6 53.3 58.8
1000 . . . 90.2 72.5 61.8 59.3 65.4
TABLE 5 Inch-sized Wall Thickness and Tolerances for PEX Plastic Pipe
Minimum Wall Thickness (t), in (tolerance is plus 12%)
Minimum Wall Thickness (t), in (tolerance is plus 12 %)
Pipe Size, in. DR 7.3 DR 8.3 DR 9 DR 11 DR 13.5 DR 15.5 DR 17 DR 21
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
6.6 Apparent Tensile Strength at Yield—When tested in accordance to 7.8, the PEX pipe shall demonstrate a minimum of 3000
psi [20.7 MPa] for PEX 0006, 3700 psi [25.5 MPa] for PEX 0008, and 4600 psi [31.7 MPa] for PEX 0009.
6.7 Degree of Crosslinking:
6.7.1 When tested in accordance with 7.9, the degree of crosslinking for PEX pipe material shall be within the range from 65 to
89 % inclusive. Depending on the process used, the following minimum percentage crosslinking values shall be achieved: 70 %
F2968/F2968M − 21
by peroxides, 65 % by electron beam, or 65 % by silane compounds. PEX pipe shall meet these minimum crosslink requirements
before the manufacturer can release this pipe for installation by the user.
6.7.2 In addition, for pipe with a wall thickness greater than 0.5 in (12.7 mm), the degree of crosslinking shall be measured at four
points separated by 90 degrees in the middle of the wall. For one of these points, measure at three points along the wall thickness
– see Fig. 1 below. Collect shaving samples, about 0.004 inin. (0.10 mm) thick, by drilling a hole in the axial pipe direction with
a ⁄8 in. (3 mm) drill to collect a 0.007 – 0.014 ounce (0.2 – 0.4 gram) sample size.
6.7.3 The degree of crosslinking over the entire wall thickness of all thick-wall pipe tested per 6.7.2 shall meet the minimum
requirements specified in 6.7.1. The degree of crosslinking shall not vary outside the limits specified in 6.7.1 at any time at any
part of the pipe.
6.8 Stabilizer Functionality—Stabilizer Functionality shall be tested in accordance with 7.10. The test need only be performed for
the original validation of pipe made from a particular compound.
6.9 Bent Pipe Hydrostatic Sustained Pressure Strength:
6.9.1 General—PEX pipe sizes and DR’s deemed suitable for bending by the pipe manufacturer shall meet the requirements in
6.9.2.
6.9.2 Cold-bent pipe, with a radius of six (6) times the outside diameter and consisting of a continuous bend length inducing not
less than 90° angle, shall meet the minimum hydrostatic sustained pressure strength requirements in 6.4 when tested in accordance
with 7.6.
6.10 Squeeze-Off—This requirement is limited to pipe sizes, wall thicknesses, squeeze procedures, and conditions deemed suitable
for squeeze-off in service by the pipe manufacturer. Squeeze-off shall be performed per Guide F1041 using tools that meet
Specification F1563. There shall be no leakage or visual evidence of splitting, cracking, breaking or reduction in 1000 h sustained
pressure category when pipe is tested in accordance with 7.12.
6.11 Elevated Temperature Service—piping materials intended for use at temperatures above 100°F [38°C]100 °F [38 °C] shall
have the PPI hydrostatic design basis (HDB) determined at the specific temperature in accordance with Test Method D2837. The
100 000-h intercept (long-term strength) shall be categorized in accordance with Table 6 and be listed as the “hydrostatic design
basis of XXX psi at XXX °F [C°] for (compound name).”
6.12 All tests shall be repeated if there is a change in the crosslinking agent, antioxidant package or the base PE resin for the PEX
compound.
FIG. 1 Sample Location for Degree of Crosslink Test on Thick-wall Pipe
F2968/F2968M − 21
TABLE 6 Pipe Category
Property Test Method Category
A B C D E F G H
Temperature, °F . 100 [38] 120 [49] 140 [60] 160 [71] 180 [82] 200 [93] . .
[°C]
Hydrostatic D2837 400 [2.8] 500 [3.4] 630 [4.3] 800 [5.5] 1000 [6.9] 1250 [8.6] 1600 [11.0] 2000 [13.8]
Design Basis,
psi [MPa]
Example: EE - At 180ºF [82ºC] the HDB is 1000 psi [6.9 MPa].
Example: EE - At 180 ºF [82 ºC] the HDB is 1000 psi [6.9 MPa].
6.13 Minimum Operating Temperature:
6.13.1 Pipe shall have a minimum operating temperature established by testing in accordance with 6.13.2. Squeeze-off te
...