ASTM D1598-23

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Designation: D1598 − 21 D1598 − 23
Standard Test Method for
Time-to-Failure of Plastic Pipe Under Constant Internal
Pressure
This standard is issued under the fixed designation D1598; 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 test method covers the determination of the time-to-failure of both thermoplastic and reinforced thermosetting/resin pipe
under constant internal pressure.
1.2 This test method provides a method of characterizing plastics in the form of pipe under the conditions prescribed.
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.
2. Referenced Documents
2.1 ASTM Standards:
D618 Practice for Conditioning Plastics for Testing
D2122 Test Method for Determining Dimensions of Thermoplastic Pipe and Fittings
D2837 Test Method for Obtaining Hydrostatic Design Basis for Thermoplastic Pipe Materials or Pressure Design Basis for
Thermoplastic Pipe Products
D2992 Practice for Obtaining Hydrostatic or Pressure Design Basis for “Fiberglass” (Glass-Fiber-Reinforced Thermosetting-
Resin) Pipe and Fittings
D2517 Specification for Reinforced Epoxy Resin Gas Pressure Pipe and Fittings
D3567 Practice for Determining Dimensions of “Fiberglass” (Glass-Fiber-Reinforced Thermosetting Resin) Pipe and Fittings
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 failure, n—occurrence of ballooning, rupture, seepage or weeping.
This test method is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test Methods.
Current edition approved Nov. 1, 2021July 1, 2023. Published November 2021July 2023. Originally approved 1958. Last previous edition approved in 20152021 as
D1598 – 15a.D1598 – 21. DOI: 10.1520/D1598-2110.1520/D1598-23
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.
*A Summary of Changes section appears at the end of this standard
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D1598 − 23
3.1.1.1 ballooning, n—any localized expansion of a pipe while under internal pressure. This is sometimes referred to as ductile
failure.
3.1.1.1.1 Discussion—Overall distention caused by applied stress is not considered to be a failure.
3.1.1.2 rupture, n—a break in the pipe wall with immediate loss of test fluid and continued loss at essentially no pressure. If
rupture is not preceded by some yielding, this may be termed a non-ductile failure.
3.1.1.3 seepage or weeping, n—test fluid passing through cracks in the pipe wall to an extent detectable visually or
electronically. A reduction in pressure will frequently enable the pipe to carry fluid without apparent evidence of loss of fluid.
3.1.2 free (unrestrained) end closure, n—a pipe specimen end closure(cap) that seals the end of the pipe against loss of internal
fluid and is fastened to the pipe specimen.
3.1.3 restrained end closure, n—a pipe specimen end closure (cap) that seals the end of the specimen against loss of internal fluid
and pressure, but is not fastened to the pipe specimen. Retained end closures rely on tie-rod(s) through the pipe specimen or on
an external structure to resist internal pressure end thrust.
4. Summary of Test Method
4.1 This test method consists of exposing specimens of pipe to a constant internal pressure while in a controlled environment. Such
a controlled environment may be accomplished by, but is not limited to, immersing the specimens in a controlled temperature water
or air bath. The time-to-failure is measured.
NOTE 1—Dimensional changes should be measured on specimens undergoing long-term strength tests. Measurements using circumferential tapes, strain
gages, or mechanical extensometers provide useful information.
5. Significance and Use
5.1 The data obtained by this test method are useful for establishing stress versus failure time relationships in a controlled
environment from which the hydrostatic design basis for plastic pipe materials can be computed. (Refer to Test Method D2837 and
Practice D2992.)
5.2 In order to determine how plastics will perform as pipe, it is necessary to establish the stress-failure time relationships for pipe
over 2 or more logarithmic decades of time (hours) in a controlled environment. Because of the nature of the test and specimens
employed, no single line can adequately represent the data, and therefore the confidence limits should be established.
NOTE 2—Some materials may exhibit a nonlinear relationship between log-stress and log-failure time, usually at short failure times. In such cases, the
10 -hour stress value computed on the basis of short-term test data may be significantly different than the value obtained when a distribution of data points
in accordance with Test Method D2837 is evaluated. However, these data may still be useful for quality control or other applications, provided correlation
with long-term data has been established.
5.3 The factors that affect creep and long-term strength behavior of plastic pipe are not completely known at this time. This
procedure takes into account those factors that are known to have important influences and provides a tool for investigating others.
5.4 Creep, or nonrecoverable deformation for pipe made of some plastics, is as important as actual leakage in deciding whether
or not a pipe has failed. Specimens that exhibit localized ballooning, however, may lead to erroneous interpretation of the creep
results unless a method of determining creep is established that precludes such a possibility. Circumferential measurements at two
or three selected positions on a specimen may not be adequate.
5.5 Great care must be used to ensure that specimens are representative of the pipe under evaluation. Departure from this
assumption may introduce discrepancies as great as, if not greater than, those due to departure from details of procedure outlined
in this test method.
6. Apparatus
6.1 Constant-Temperature System—A water bath or other fluid bath equipped so that uniform temperature is maintained
throughout the bath. This may require agitation. If an air or other gaseous environment is used, provision shall be made for
adequate circulation. The test may be conducted at 73 °F (23 °C) or other selected temperatures as required and the temperature
tolerance requirements shall be 63.6 °F (62.0 °C).
D1598 − 23
6.2 Pressurizing System—Any device that is capable of continuously applying constant internal pressure on the specimen may be
used. The device shall be capable of reaching the test pressure without exceeding it and of holding the pressure within the tolerance
shown in 6.6 for the duration of the test.
6.3 Pressure Gage—A pressure gage or pressure transducer having an accuracy sufficient to meet the pressure tolerance
requirements of 6.6 is required.
6.4 Timing Device—A time meter connected to the pressurized fluid side of the system through a pressure or flow switch, or both.
The timing device and pressure or flow switch, or both, together shall be capable of measuring the time when the specimen is at
98 % or more of test pressure with sufficient accuracy to meet the tolerance requirements of 6.6.
6.5 Specimen End Closures—Either free-end or restrained-end closures that will withstand the maximum test pressures may be
used. Closures shall be designed so that they do not cause failure of the specimen. Free-end closures shall be used for referee tests
for thermoplastic pipe.
NOTE 3—Free-end closures fasten to the specimen so that internal pressure produces longitudinal tensile stress in addition to hoop. Compared to free end
closure specimens, stresses in the wall of restrained-end closure specimens act in the hoop and radial directions only. Because of this difference in loading,
the equivalent hoop stress in free-end closure specimens of solid wall thermoplastic pipe are approximately 11 % lower than in restrained-end closure
specimens tested at the same pressure. The test results for each specimen and the LTHS will reflect this difference in test method.
6.6 Time and Pressure Tolerance—When added together, the tolerance for the timing device and the tolerance for the pressure gage
shall not exceed 62 %.
7. Test Specimens
7.1 Pipe Specimen Length—For pipe sizes of 6 in. (150 mm) or less, the specimen length between end closures shall be not less
than five times the nominal outside diameter of the pipe, but in no case less than 12 in. (300 mm). The 12 in. (300 mm) minimum
specimen length requirement sh
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