ASTM F3378/F3378M-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: F3378/F3378M −22
Standard Specification for
Crosslinkable Polyethylene (CX-PE) Pipe
ThisstandardisissuedunderthefixeddesignationF3378/F3378M;thenumberimmediatelyfollowingthedesignationindicatestheyear
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 1.6 Joining of CX-PE pipes made in accordance with this
specification is outside the scope of this specification. For
1.1 This specification covers outside diameter controlled
guidance on the joining of CX-PE pipe consult Practice F3507
crosslinkablepolyethylene(CX-PE)pipeproducedinsizesDN
and manufacturer’s recommendations.
25 to 630 and NPS 1 to 24 in various dimension ratios.
Includedinthisspecificationarerequirementsandtestmethods 1.7 This specification references notes, footnotes, and
for the determination of the long-term hydrostatic strength, appendixes, which provide non-mandatory explanatory mate-
hydrostatic burst pressure, hydrostatic sustained pressure, UV rial. Excluding table footnotes which are mandatory, notes,
weathering resistance, initial and ultimate degree of footnotes and information in parentheses shall not be consid-
crosslinking, workmanship, and marking. ered as requirements of this specification.
1.2 This specification shall not be applied to crosslinked 1.8 The values stated in either SI units or inch-pound units
products, specifically PEX pipe or tubing. are to be regarded separately as standard. The values stated in
each system are not necessarily exact equivalents; therefore, to
NOTE 1—CX-PE is a different designation separate from conventional
ensure conformance with the standard, each system shall be
PEX materials, specifically with regard to the crosslinking rate,
used independently of the other, and values from the two
installation, and commissioning processes.
systems shall not be combined.
1.3 The pipe covered by this specification is intended for
1.9 This standard does not purport to address all of the
pressure and non-pressure applications. Fluids such as non-
safety concerns, if any, associated with its use. It is the
potable water, multi-phase mixed fluids, crude oils, gases, and
responsibility of the user of this standard to establish appro-
chemical solutions containing some water are allowed to be
priate safety, health, and environmental practices and deter-
transported in pipe made in accordance with this standard.
mine the applicability of regulatory limitations prior to use.
Permissible operating temperatures for commissioned piping
1.10 This international standard was developed in accor-
systems constructed from CX-PE pipe manufactured in accor-
dance with internationally recognized principles on standard-
dance with this specification are ≤ 200 °F [93 °C].
ization established in the Decision on Principles for the
1.4 Pipe produced in accordance with this specification is
Development of International Standards, Guides and Recom-
intended to be crosslinked during or after installation. The
mendations issued by the World Trade Organization Technical
procedures and practices to be used for the installation and
Barriers to Trade (TBT) Committee.
crosslinking of the CX-PE pipe are outside the scope of this
specification. Manufacturer’s recommendations for the com-
2. Referenced Documents
missioning of CX-PE pipe are used to ensure that the perfor-
2.1 ASTM Standards:
mance of the completed piping system meets design expecta-
D638 Test Method for Tensile Properties of Plastics
tions.
D792 Test Methods for Density and Specific Gravity (Rela-
NOTE 2—The difference between pipes made in accordance with this
tive Density) of Plastics by Displacement
specification and PEX pipes made in accordance with Specification F2905
D1505 Test Method for Density of Plastics by the Density-
isthatthefinalcrosslinkingprocessiscompletedaspartofinstallationand
Gradient Technique
commissioning as opposed to crosslinking taking place in the manufac-
turing facility. D1598 Test Method for Time-to-Failure of Plastic Pipe
Under Constant Internal Pressure
1.5 This specification includes requirements to demonstrate
D1599 Test Method for Resistance to Short-Time Hydraulic
a minimum level of performance in service.
Pressure of Plastic Pipe, Tubing, and Fittings
This specification is under the jurisdiction ofASTM Committee F17 on Plastic
Piping Systems and is the direct responsibility of Subcommittee F17.68 on Energy For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Piping Systems. contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
Current edition approved March 1, 2022. Published March 2022. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
F3378_F3378M–22 the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
F3378/F3378M − 22
D1600 Terminology forAbbreviatedTerms Relating to Plas- 2.4 PPI Standard:
tics TR-3 2021 – HDB/HDS/PDB/SDB/MRS/CRS Policies
D1603 Test Method for Carbon Black Content in Olefin 2.5 Military and Federal Standards:
Plastics FED-STD 123G Marking for Shipment (Civil Agencies)
D2122 Test Method for Determining Dimensions of Ther- MIL-STD 129P Military Marking for Shipment and Storage
moplastic Pipe and Fittings
3. Terminology
D2290 Test Method for Apparent Hoop Tensile Strength of
Plastic or Reinforced Plastic Pipe
3.1 Definitions—Unless otherwise specified, definitions are
D2565 Practice for Xenon-Arc Exposure of Plastics In-
inaccordancewithTerminologyF412,andabbreviationsarein
tended for Outdoor Applications
accordance with Terminology F412 and Terminology D1600.
D2765 Test Methods for Determination of Gel Content and
3.2 Definitions of Terms Specific to This Standard:
Swell Ratio of Crosslinked Ethylene Plastics
3.2.1 commission, v—a series of actions taken after instal-
D2837 Test Method for Obtaining Hydrostatic Design Basis
lation to bring a new system into working condition.
forThermoplasticPipeMaterialsorPressureDesignBasis
3.2.2 crosslinked pipe, n—pipe that is crosslinked to a
for Thermoplastic Pipe Products
measured gel content level of ≥ 65 %.
D3895 Test Method for Oxidative-Induction Time of Poly-
3.2.3 crosslinkable polyethylene, CX-PE, n—a polyethylene
olefins by Differential Scanning Calorimetry
D4218 Test Method for Determination of Carbon Black compound that has been chemically modified so that crosslinks
will form when the compound is exposed to heat and moisture.
Content in Polyethylene Compounds by the Muffle-
Furnace Technique 3.2.3.1 Discussion—When pipe made from CX-PE reaches
a level of crosslinking ≥65 % it is considered fully crosslinked
D4329 Practice for Fluorescent Ultraviolet (UV) Lamp Ap-
paratus Exposure of Plastics and is referred to as crosslinked pipe in accordance with this
standard.
D4364 Practice for Performing OutdoorAccelerated Weath-
ering Tests of Plastics Using Concentrated Sunlight
3.2.4 design factor, DF, n—a number between 0 and 1, that
F412 Terminology Relating to Plastic Piping Systems
the HDB is multiplied by to determine the HDS. This value is
F876 SpecificationforCrosslinkedPolyethylene(PEX)Tub-
intended to contribute to the certainty that pipe will not fail in
ing
the service it is designed for.
F2023 Test Method for Evaluating the Oxidative Resistance
3.2.5 nominal diameter, DN, adj—a designation for SI unit
of Crosslinked Polyethylene (PEX) Pipe, Tubing and
of outside diameter-controlled pipe sizes that generally comply
Systems to Hot Chlorinated Water
with outside diameters specified in ISO 161-1.
F2657 Test Method for Outdoor Weathering Exposure of
3.2.6 nominal pipe size, NPS, adj—a designation for inch-
Crosslinked Polyethylene (PEX) Tubing
pound unit outside diameter-controlled pipe sizes that gener-
F2905 Specification for Crosslinked Polyethylene (PEX)
ally comply with outside diameters specified in ANSI B36.10.
Line Pipe For Oil and Gas Producing Applications
F3203 Test Method for Determination of Gel Content of 3.2.7 maximum allowable operating pressure, MAOP,
Crosslinked Polyethylene (PEX) Pipes and Tubing n—the estimated maximum continuous pressure a pipe is
F3507 Practice for Butt-Fusion Joining of Crosslinkable capableofwithstandingatthemaximumoperatingtemperature
Polyethylene (CX-PE) Pipe and Tubing of a piping system with a high degree of certainty that failure
of the pipe will not occur.
2.2 ANSI Standard:
B36.10 Standard for Welded and Seamless Wrought Steel
4. Materials
Pipe
4.1 Basic Materials—CX-PE compound used for produc-
2.3 ISO Standards:
tion of pipe in accordance with this specification, and for
ISO 14531-1 Plastics pipes and fittings — Crosslinked
optional co-extruded stripes and layers shall be made from
polyethylene (PE-X) pipe systems for the conveyance of
polyethylene compounds which have been made crosslinkable
gaseous fuels — Metric series — Specifications — Part 1:
during polyethylene compound manufacture by chemically
Pipes
grafting reactive molecules (for example, vinyl trimethoxy
ISO161-1 Thermoplasticspipesfortheconveyanceoffluids
silane)ontopolyethylenemolecules,orbycopolymerizationof
- Nominal outside diameters and nominal pressures - Part
reactive molecules with ethylene to create a modified polyeth-
1: Metric series
ylene compound. Compounds and pipes that are produced by
ISO 9080 Plastics Piping and Ducting Systems - Determi-
other means such as peroxide crosslinking and radiation
nation of The Long-Term Hydrostatic Strength of Ther-
crosslinking,donotmeettherequirementsofthisspecification.
moplastics Materials in Pipe Form by Extrapolation
CX-PE compounds are crosslinked by added heat and water
(see manufacturer’s recommendations).
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St.,
4th Floor, New York, NY 10036, http://www.ansi.org. Available from Plastics Pipe Institute (PPI), 105 Decker Court, Suite 825,
Available from International Organization for Standardization (ISO), ISO Irving, TX 75062, http://www.plasticpipe.org.
Central Secretariat, Chemin de Blandonnet 8, CP 401, 1214 Vernier, Geneva, Available from DLA Document Services, Building 4/D, 700 Robbins Ave.,
Switzerland, https://www.iso.org. Philadelphia, PA 19111-5094, http://quicksearch.dla.mil.
F3378/F3378M − 22
4.2 Density—When tested in accordance with 7.4, CX-PE 5.6.1 The CX-PE materials and any compounds used for
compound shall have a minimum density of 0.033 lb./in or striping or outer layer co-extrusion shall contain sufficient
[0.926 g/cm ]. stabilizers to protect the pipe from UVdegradation for a period
of not less than six months.
4.3 Degree of Crosslinking—When CX-PE compound is
5.6.2 CX-PE pipe containing between 2.0 wt. % and 3.0 wt.
fully crosslinked and tested in accordance with 7.6, it shall
% well dispersed carbon black shall be considered to be
have minimum degree of crosslinking (gel content) of 65 %.
stabilized against UV exposure for not less than ten years. The
4.4 Hydrostatic Design Basis (HDB) of Crosslinked
carbonblackcontentinblackCX-PEpipeshallbemeasuredin
Compound—CX-PE compound in pipe form and fully
accordancewiththerequirementsofeitherTestMethodD1603
crosslinked, having a degree of crosslinking (gel content)
or Test Method D4218.
≥65 %,shallhaveanHDBvaluedeterminedandcategorizedin
5.6.3 The maximum UV exposure time for CX-PE pipe not
accordance with the requirements of Test Method D2837.
containing a minimum of 2.0 wt. % carbon black, shall be
4.5 Thermal Stability—When CX-PE compound is tested in
determined by exposing representative pipe samples to natural
accordance with D3895 at 392 °F [200 °C], it shall have an
weathering in accordance with Test Method F2657,orISO
oxidative induction time of greater than 20 minutes.
14531-1Annex C.Alternatively accelerated UV weathering in
accordance with Practice D2565, or Practice D4329, or Prac-
4.6 UV Resistance and Color:
tice D4364 are permitted to be used. The minimum total UV
4.6.1 The CX-PE materials and any compounds used for
exposure tested with shall be 218 MJ/m which shall be
striping or outer layer co-extrusion shall contain sufficient
considered equivalent to six months of outdoor weathering
stabilizers or carbon black to protect the pipe from UV
exposure as described in Test Method F2657.Atotal solar UV
degradation for a period of not less than six months
radiation value of 339 MJ/m per year shall be considered the
amount of natural UV weathering exposure per year when
5. Product Qualification
determining the maximum UV exposure time.
5.1 Product qualification testing shall be performed to
5.6.4 If natural weathering in accordance with Test Method
demonstrate the suitability of a CX-PE compound in pipe form
F2657 or ISO 14531-1 Annex C is used, and post exposure
in accordance with this specification. Unless otherwise
testinginaccordancewithTestMethodF2657isexcluded,post
specified, product qualification tests are conducted on any
exposure testing per the requirements of this standard shall be
representative size of pipe.
used to determine maximum UV exposure time. Alternatively,
5.2 Tensile Elongation—When crosslinked CX-PE pipe is
for CX-PE pipes that have a maximum UV exposure time
tested in accordance with 7.8, it shall have a tensile elongation
determinedwhentestedinaccordancewithTestMethodF2657
at break exceeding 350 %.
post exposure requirements, no further post exposure testing is
required
5.3 Hydrostatic Design Basis (HDB) of Crosslinked Pipe—
CX-PE compound in pipe form and fully crosslinked, having a
5.6.5 FollowingUVweatheringexposure,CX-PEpipeshall
degree of crosslinking (gel content) ≥65 %, shall have an HDB meet the tensile elongation and OIT requirements of 5.2 and
value determined and categorized in accordance with the
4.5.
requirements of Test Method D2837.
5.3.1 The CX-PE crosslinked compound, when fully
6. Pipe Requirements
crosslinked, shall have a minimum HDB value of 1250 psi at
6.1 The requirements of 6.2 through 6.11 shall apply to
73 °F [8.62 MPa at 23 °C], 800 psi at 180 °F [5.52 MPa at
CX-PE pipe.
82 °C] and 630 psi at 200 °F [4.34 MPa at 93 °C].
6.2 Workmanship—The pipe shall be homogeneous
NOTE 3—Where a Long-Term Hydrostatic Strength (LTHS) value is
throughout and free of visible cracks, holes, foreign inclusions,
needed for an application at a temperature intermediate between the
or other defects. The pipe shall be as uniform as commercially
established lower HDB and established higher temperature HDB values,
interpolation may be used. Refer to the calculations provided in The
practicable in color, opacity, density, and other physical prop-
Plastics Pipe Institute’s Technical Report TR-3, Part D2 -Policy for
erties. Pipe made in accordance with this specification that is
Determination of Long- Term Strength by Temperature Interpolation
co-extruded with an external color layer or external color
5.4 Stabilizer Functionality—The functionality of a stabi-
stripes shall be acceptable.
lizer in a specific CX-PE compound shall be verified by
6.2.1 Preservation—Pipe produced in accordance with this
hydrostatic testing of pipe in accordance with 7.9, or with an
specification shall be handled and stored in such a way as to
ISO 9080 data set for pipe made from the compound contain-
preserve the quality and workmanship of the pipe. This shall
ing data at 110 °C that shows data points at a stress of greater
include appropriate storage to manage weathering of the pipe
than or equal to 3.24 MPa and time greater than 8000 h.
(for example, use of tarps over pallets of pipe stored outdoors).
5.5 Chlorine-Thermal Oxidative Stabilization—Resistance
6.3 Pipe Diameter—The outside diameter of the pipe shall
to thermo-oxidation shall be determined for CX-PE pipe in
be in accordance with Table 1 or Table 2 when measured in
accordance with Test Method F2023. Tubing made in accor-
accordance with Test Method D2122. The outside diameter
dancewiththedimensionalrequirementsofSpecificationF876
measurement shall be taken at a distance at least 1.5 times the
for NTS ⁄2 shall be tested.
average outside diameter or 11.8 in. or 300 mm, whichever is
5.6 UV Resistance and Color: less, from the cut end of the pipe. The pipe manufacturer shall
F3378/F3378M − 22
TABLE 1 DN Size Pipe – Diameter and Wall Thickness, mm
Nom. Size Outside Diameter Minimum Wall Thickness– (tolerance -0/+12 %)
(DN)
Minimum Tolerance OOR DR 7.4 DR 9 DR 11 DR 13.6 DR 16.2 DR 17
25 25.0 0.3 1.2 3.5 3.0 2.3 – – –
32 32.0 0.3 1.3 4.4 3.6 3.0 2.4 – –
40 40.0 0.4 1.4 5.5 4.5 3.7 3.0 2.5 2.4
50 50.0 0.5 1.4 6.9 5.6 4.6 3.7 3.1 3.0
63 63.0 0.6 1.6 8.6 7.1 5.8 4.7 3.9 3.8
75 75.0 0.7 1.6 10.3 8.4 6.8 5.6 4.6 4.5
90 90.0 0.9 1.8 12.3 10.1 8.2 6.7 5.6 5.4
110 110.0 1.0 2.2 15.1 12.3 10.0 8.1 6.8 6.6
125 125.0 1.2 2.5 17.1 14.1 11.4 9.2 7.7 7.4
140 140.0 1.3 2.8 19.2 15.7 12.7 10.3 8.7 8.3
160 160.0 1.5 3.2 21.9 17.9 14.6 11.8 9.9 9.5
180 180.0 1.7 3.6 24.6 20.1 16.4 13.3 11.1 10.7
200 200.0 1.8 4.0 27.4 22.4 18.2 14.7 12.4 11.9
225 225.0 2.1 4.5 30.8 25.2 20.5 16.6 13.9 13.4
250 250.0 2.3 5.0 34.2 27.9 22.7 18.4 15.5 14.8
280 280.0 2.6 9.8 38.3 31.3 25.4 20.6 17.3 16.6
315 315.0 2.9 11.1 43.1 35.2 28.6 23.2 19.5 18.7
355 355.0 3.4 12.5 48.5 39.7 32.2 26.1 21.9 21.1
400 400.0 3.6 14.0 54.7 44.7 36.3 29.4 24.7 23.8
450 450.0 4.2 15.6 61.5 50.3 40.9 33.1 27.8 26.7
500 500.0 4.6 17.5 – 55.8 45.4 36.8 30.9 29.7
560 560.0 5.2 19.6 – 62.5 50.8 41.2 34.6 33.2
630 630.0 5.8 22.1 – 70.3 57.2 46.3 38.9 37.4
TABLE 2 NPS Pipe – Diameter and Wall Thickness, in.
Nominal Outside Diameter Minimum Wall Thickness – tolerance +12 %
Pipe Size
Average Tolerance OOR DR 7 DR 7.3 DR 9 DR 11 DR 13.5 DR 17
(NPS)
1 1.315 ±0.005 0.03 0.188 0.180 0.146 0.120 – –
1 ⁄4 1.660 ±0.005 0.03 0.237 0.227 0.184 0.151 0.123 –
1 ⁄2 1.900 ±0.006 0.06 0.271 0.260 0.211 0.173 0.141 –
2 2.375 ±0.006 0.06 0.339 0.325 0.264 0.216 0.176 0.140
3 3.500 ±0.008 0.06 0.500 0.479 0.389 0.318 0.259 0.206
4 4.500 ±0.009 0.10 0.643 0.616 0.500 0.409 0.333 0.265
6 6.625 ±0.011 0.12 0.946 0.908 0.736 0.602 0.491 0.390
8 8.625 ±0.013 0.24 1.232 1.182 0.958 0.784 0.639 0.507
10 10.750 ±0.015 0.24 1.536 1.473 1.194 0.977 0.796 0.632
12 12.750 ±0.017 0.28 1.821 1.747 1.417 1.159 0.944 0.750
14 14.000 ±0.063 – 2.000 1.918 1.556 1.273 1.037 0.824
16 16.000 ±0.072 – 2.286 2.192 1.778 1.455 1.185 0.941
18 18.000 ±0.081 – 2.571 2.466 2.000 1.636 1.333 1.059
20 20.000 ±0.090 – 2.857 2.740 2.222 1.818 1.481 1.176
22 22.000 ±0.099 – 3.143 3.014 2.444 2.000 1.630 1.294
24 24.000 ±0.108 – 3.429 3.288 2.667 2.182 1.778 1.412
ensure that any change in diameter of the pipe during cross- Table 1 or Table 2 for the applicable size pipe. Measure out of
linking will result in crosslinked pipe that conforms to the roundness in accordance with Test Method D2122.
tolerances stated in Table 1 or Table 2.
NOTE 5—Irregular outside surface conditions from the extrusion line
6.3.1 Toe-In—When measured in accordance with Test
processingequipmentthatarenotfieldcorrectiblecanaffectthesuitability
Method D2122, the outside diameter at the cut end of the pipe
of pipe for joining with devices that secure or seal to the pipe outside
shall not be more than 1.5 % smaller than the outside diameter surface, especially electrofusion devices.
in accordance with Table 1 or Table 2.
6.4 Pipe Wall Thickness—Pipe wall thickness shall be as
6.3.2 Ovality—Pipe ovality (elliptical shape) when exiting
specified in Table 1 or Table 2 when measured in accordance
production line processing equipment but before coiling or
with Test Method D2122.
packaging for shipment shall not exceed 5 % when determined
6.5 Special Sizes—Outside diameter or wall thickness not
in accordance with 7.10.
specified in Table 1 or Table 2 shall be acceptable by
NOTE 4—Ovality is a field correctible condition that results from
agreement between the manufacturer and the purchaser. If not
packagingorstorage.Whencoiled,pipewilldeflecttoanovalorelliptical
otherwise specified, the total tolerance on special size outside
profile, and when packaged or stored, higher DR pipe may deflect to an
diameter shall not exceed +0.90 % of the minimum special
oval or elliptical profile. If necessary, commercially available equipment
can be applied to minimize percent ovality during field joining or
outside diameter or 60.45 % of the average special outside
installation.
diameter. If not otherwise specified, the tolerance on special
6.3.3 Out of Roundness (OOR)—The measured out of size wall thickness shall be +12 % of the minimum special size
roundness shall be less than or equal to the OOR specified in wall thickness for NPS 12 and smaller special sizes.
F3378/F3378M − 22
6.6 Short Term Strength—CX-PE pipe specimens shall be carbonblackcontentinblackCX-PEpipeshallbemeasuredin
testedinaccordancewith7.5todeterminethetestpressure,P , accordancewiththerequirementsofeitherTestMethodD1603
T
at 73 °F or [23 °C] for each pipe size and SDR or DR. The or Test Method D4218.
calculation of the hoop stress shall be made using the initially
7. Test Methods
measuredminimumwallthicknessanddiameterofthepipe.At
7.1 Conditioning—Specimens shall be conditioned in circu-
specimen failure, the hoop stress, S, shall exceed 2700 psi or
latingairat73 °F 64 °For[23 °C 62°C]and ≤55 %relative
[18.6 MPa].
humidity for not less than 16 h prior to testing, for those tests
6.7 Degree of Crosslinking:
where conditioning is required and not otherwise specified.
6.7.1 Within five days prior to shipment by the
7.2 Test Conditions—Tests shall be conducted at 73 °F
manufacturer, the degree of crosslinking (gel content) of
64 °F or [23 °C 6 2 °C] and ≤ 55 % relative humidity, unless
minimally crosslinked CX-PE pipe shall be less than 30 %
otherwise specified in the test methods or in this specification.
when tested in accordance with 7.6.
6.7.2 In the event that prior to shipment, the pipe manufac-
7.3 Sampling:
ture determines that CX-PE pipe is crosslinked to greater than
7.3.1 Enough pipe shall be selected and tested to determine
30 %, the manufacturer is permitted to ship the pipe with
conformance with this specification. In the case of no prior
agreement from the purchaser to accept pipe with higher than
agreement, random samples selected by the testing laboratory
specified degree of crosslinking. In this case the pipe shall be
shall be deemed adequate.
clearly marked to indicate that joining by butt fusion is not
7.3.2 It is permitted to test CX-PE pipe properties specified
recommended for the batch of CX-PE pipe in question.
in Section 5 of this specification using pipe or tubing samples
6.7.3 Fully crosslinked CX-PE pipe shall have a degree of
madeindimensionsthatdonotconformwiththisspecification.
crosslinking between 65 % and 89 % inclusive when tested in
(For example, hydrostatic, thermo-oxidative resistance, and
accordancewith7.6.Thepipemanufacturershallusehotwater
UVresistance testing are permitted to be performed on NTS ⁄2
or low-pressure steam after extrusion to crosslink pipe samples
SDR 9 tubing.)
prior to testing.
7.4 Density—The density of CX-PE pipe shall be deter-
6.8 Sustained Hydrostatic Strength (165 h)—CX-PE pipe
mined in accordance with Test Method D1505, or Test Meth-
specimens that are minimally crosslinked (<30 %) shall be ods D792, using three specimens. Specimens for these tests
tested in accordance with 7.7 using Eq 1 to determine the test
shall be taken from repre
...