ASTM F1588-96(2002)

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An American National Standard
Designation:F 1588–96 (Reapproved 2002)
Standard Test Method for
Constant Tensile Load Joint Test (CTLJT)
This standard is issued under the fixed designation F 1588; 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 (e) indicates an editorial change since the last revision or reapproval.
1. Scope 2.3 Code of Federal Regulations:
OPS Part 192, Title 49
1.1 The constant tensile load joint test (CTLJT) is designed
todemonstratethatajointinaplasticpipingsystemisresistant
3. Terminology
to the effects of long-term creep.
3.1 Definitions:
1.1.1 The joint is subjected to an internal pressure at least
3.1.1 General—Definitions are in accordance with Test
equaltoitsoperatingpressureandasustainedaxialtensileload
Method D 638 andTerminology F 412, unless otherwise speci-
for a specified time period, usually 1000 h. The joint shall not
fied. Abbreviations are in accordance with Terminology
leak, nor may the pipe completely pull out for the test duration.
D 1600.
The total axial stress is set by the referencing document.
3.1.2 The gas industry terminology used in this test method
1.1.2 Some typical conditions for testing of joints on poly-
is in accordance with the definitions given in ANSI B31.8 or
ethylene pipe are described in Appendix X1.
OPS Part 192, Title 49, unless otherwise indicated.
1.2 This test is usually performed at 73°F (22.8°C).
3.2 Definitions of Terms Specific to This Standard:
1.3 TheCTLJTwasdevelopedtodemonstratethelong-term
3.2.1 mechanical joint, Category 1—a mechanical joint
resistance to pullout of mechanical joints on polyethylene gas
designthatprovidesasealplusaresistancetoforceonthepipe
pipe. The CTLJT has also been successfully applied to the
end, equal to or greater than that which will cause a permanent
evaluation of other components of plastic piping systems.
deformation of the pipe or tubing. (D 2513)
These applications are discussed in Appendix X1.
3.2.2 mechanical joint, Category 3—a mechanical joint
1.4 This standard does not purport to address all of the
design that provides a seal plus a pipe restraint rating equiva-
safety concerns, if any, associated with its use. It is the
lent to the anticipated thermal stresses occurring in a pipeline.
responsibility of the user of this standard to establish appro-
This category has a manufacturers’ pipe-end restraint that
priate safety and health practices and determine the applica-
allows slippage at less than the value required to yield the pipe.
bility of regulatory limitations prior to use.
(D 2513)
2. Referenced Documents 3.2.3 pipe—refers to both pipe and tubing.
2.1 ASTM Standards:
4. Summary of Test Method
D 638 Test Method for Tensile Properties of Plastics
4.1 A joint is subjected to a sustained axial load for a
D 1600 Terminology for Abbreviated Terms Relating to
2 specified period of time (usually 1000 h).The test duration and
Plastics
the actual test conditions (axial stress, internal pressure, test
D 2122 Test Method for Determining Dimensions of Ther-
3 duration, and test temperature) are either specified by a
moplastic Pipe and Fittings
referencing document or, for new or unique applications,
D 2513 Specification for Thermoplastic Gas Pressure Pipe,
3 agreed upon between the user and the manufacturer. X1.2
Tubing, and Fittings
3 contains a background discussion of axial stress values and
F 412 Terminology Relating to Plastic Piping Systems
axial load determination.
2.2 ANSI Standard:
4 4.2 The joint is made to plastic pipe of the type, grade, size,
B31.8 Gas Transmission and Distribution Piping Systems
and dimension ratio to be used in the final application. The
axial tensile stress should be as high as possible, but shall be
This test method is under the jurisdiction of ASTM Committee F17 on Plastic lower than the stress at which the plastic material continues to
Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test
stretch and finally yields (the long-term yield strength) (see
Methods.
Note 1).
Current edition approved March 10, 1996. Published May 1996. Originally
published as F 1588 – 95. Last previous edition F 1588 – 95.
Annual Book of ASTM Standards, Vol 08.01.
Annual Book of ASTM Standards, Vol 08.04.
4 5
Available fromAmerican National Standards Institute (ANSI), 25 W. 43rd St., Available from Superintendent of Documents, Government Printing Office,
4th Floor, New York, NY 10036. Washington, DC 20402.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
F 1588–96 (2002)
NOTE 1—During the first hours of a test, the pipe elongates measurably.
cylinder and then to monitor a pressure gage placed in the
Elongation continues for the duration of the test at a decaying rate.
pressurization line to the cylinder during the test.
6.3 Pressure Gage—Each assembly shall have a pressure
4.3 A joint passes this test if it does not leak and does not
gage to monitor internal pressure on the test assembly. The
pull out or allow slippage in excess of the manufacturers’
gage shall be able to measure the test pressure to within an
specified design slippage during the test duration.
accuracy of 1 % or better.
4.4 If a pipe in the test assembly yields before the specified
minimum test time is attained, the total stress is above the 6.4 Test Assembly:
long-term yield strength of that pipe and the test shall be
6.4.1 The test assembly is capped and verified to be leak
performed again at a stress level calculated to be below the
tight.Attachment devices that ensure straight line axial loading
long-term yield strength of the pipe.
shall be used at each end to attach the test assembly to the
loading device. The test assembly may contain more than one
5. Significance and Use
joint of the size under evaluation (see Note 3).
5.1 This test method was designed to be used to validate the
NOTE 3—There are many configurations possible with the wide variety
long-term resistance to pullout of joints designed for use in
of joints that are available. If the mechanical joint to be tested is suitable
plastic natural gas piping systems.
for the purpose, it can be used to cap the pipe ends.
5.2 This test method is used in addition to the short-term
6.4.2 The minimum length is three pipe diameters between
tests required by OPS Part 192.283b, Title 49. Informal
fittings (stiffener ends). Elongation is proportional to specimen
versions of this test method are used by manufacturers and
length. It is important to allow sufficient space in the apparatus
utilities to demonstrate that a joint is resistant to the effects of
to provide for anticipated elongation of the test specimen for
long-term creep and meets the requirements for classification
the duration of the test.
as a Category 1 or a Category 3 joint in accordance with
Specification D 2513.
7. Precautions and Safety Considerations
5.3 This test method may also be applicable for the deter-
7.1 Each test fixture and joint assembly shall be designed to
mination of the effects of a sustained axial load on joints or
other components of plastic piping systems designed for other safely accommodate a sudden unexpected failure in any part of
the test assembly. Both fixture and joint(s) shall be regularly
applications. Test parameters and the internal pressurizing
fluid, if any, should be listed in the referencing document. inspected for safety. Joint pullouts usually occur unexpectedly
and proceed from start to finish in seconds. Failure may be
5.4 Documents that reference this test method for products
accompanied by the sudden release of the internal pressure or
other than joints shall specify test conditions and performance
a falling test assembly, or both.
requirements. In general, such products pass this test if they
maintain their structural integrity, do not leak, and perform to 7.2 It is strongly recommended that water be used as the
specification during and after the test.
pressurizingfluidwhentestingsystemsthatmayfailinabrittle
manner (specifically PVC systems). If that is not possible, the
6. Apparatus
test specimens shall be placed in a strong chamber at all times
when pressurized (see Note 4).
6.1 Loading Methods:
6.1.1 Any loading method that maintains the correct, in-line
NOTE 4—For example, after 938 h of uneventful testing, one 6-in. IPS
tensile load on the joint (within 62 %) for the test duration is
transition joint rapidly pulled apart. There was no indication of pipe
acceptable. Loading methods successfully employed for all movement when inspected 5 min before failure.
size loads include lever arms, hydraulic cylinders, and air
8. Test Specimens
cylinders.
6.1.2 Dead weight (a pile of scrap steel or iron) has worked
8.1 Pipe Specimen Selection:
well for loads up to 1 ton (907 kg) (see Note 2).
8.1.1 For tests of fittings intended for use in natural gas
distribution systems, the pipe supply used for the tests shall
NOTE 2—To provide an adequate stress level for ⁄8 in. DR 7 PE tubing,
about 200 lb (90 kg) are required. Pipe 2 in. SDR11 PE requires about have a print line signifying that it was manufactured to the
2000 lb (907 kg).
requirements of Specification D 2513.
8.1.2 Pipe specimens used for fittings tests shall meet the
6.1.3 Hydraulic and air-powered loading frames have been
dimensional requirements of the referencing document. (See
constructed to provide up to 50 000 lb (22 680 kg) for tests on
Note 5.)The dimensions of the pipe specimens selected for use
3-in. IPS through 8-in. I
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