ASTM D5365-99
(Test Method)Standard Test Method for Long-Term Ring-Bending Strain of "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
Standard Test Method for Long-Term Ring-Bending Strain of "Fiberglass" (Glass-Fiber-Reinforced Thermosetting-Resin) Pipe
SCOPE
1.1 This test method covers a procedure for determining the long-term ring-bending strain (S b) of "fiberglass" pipe. Both glass-fiber-reinforced thermosetting-resin pipe (RTRP) and glass-fiber-reinforced polymer mortar pipe (RPMP) are "fiberglass" pipes.
1.2 The values stated in inch-pound units are to be regarded as the standard. The SI units given in parentheses are for information only.
1.3 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. A specific warning statement is given in 9.5.
Note 1—There is no similar or equivalent ISO standard.
General Information
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Standards Content (Sample)
NOTICE: This standard has either been superseded and replaced by a new version or discontinued.
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Designation: D 5365 – 99 An American National Standard
Standard Test Method for
Long-Term Ring-Bending Strain of “Fiberglass” (Glass-
Fiber-Reinforced Thermosetting-Resin) Pipe
This standard is issued under the fixed designation D 5365; 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 setting resin. The composite structure may contain aggregate,
granular or platelet fillers, thixotropic agents, pigments, or
1.1 This test method covers a procedure for determining the
dyes, thermoplastic or thermosetting liners or coatings may be
long-term ring-bending strain (S ) of “fiberglass” pipe. Both
b
included.
glass-fiber-reinforced thermosetting-resin pipe (RTRP) and
3.2.3 reinforced plastic mortar pipe (RPMP)—fiberglass
glass-fiber-reinforced plastic mortar pipe (RPMP) are “fiber-
pipe with aggregate.
glass” pipes.
3.2.4 reinforced thermosetting resin pipe (RTRP)—
1.2 The values stated in inch-pound units are to be regarded
fiberglass pipe without aggregate.
as the standard. The SI units given in parentheses are for
information only.
4. Summary of Test Method
1.3 This standard does not purport to address all of the
4.1 This test method consists of subjecting submerged-pipe
safety concerns, if any, associated with its use. It is the
ring specimens to various increasing deflections induced by a
responsibility of the user of this standard to establish appro-
constant load and monitoring the time to failure. A minimum of
priate safety and health practices and determine the applica-
18 samples are required. Test temperatures are obtained by
bility of regulatory limitations prior to use. Specific precau-
testing in a fluid environment where the temperature is
tionary statements are given in Note 8.
controlled.
NOTE 1—There is no similar or equivalent ISO standard.
4.2 The long-term ring-bending strain is obtained by an
extrapolation to 50 years of a log-log linear regression line for
2. Referenced Documents
failure strain versus time.
2.1 ASTM Standards:
NOTE 2—It is the consensus of Subcommittee D 20.23 that the log-log
D 883 Terminology Relating to Plastics
linear regression analysis of test data is a conservative approach and is
D 1600 Terminology of Abbreviated Terms Relating to
representative of standard industry practice. However, a task group has
Plastics
been formed to evaluate alternative non-linear analysis methods.
D 3567 Practice for Determining Dimensions of “Fiber-
glass” (Glass–Fiber–Reinforced Thermosetting Resin)
5. Significance and Use
Pipe and Fittings
5.1 This test method determines the long-term ring-bending
strain of pipe when deflected under constant load and im-
3. Terminology
mersed in a chemical environment. It has been found that
3.1 Definitions:
effects of chemical environments can be accelerated by strain
3.1.1 General—Definitions are in accordance with Termi-
induced by deflection. This information is useful and necessary
nology D 883 and abbreviations are in accordance with Termi-
for the design and application of buried fiberglass pipe.
nology D 1600 unless otherwise indicated.
NOTE 3—Pipe of the same diameter but of different wall thicknesses
3.2 Definitions of Terms Specific to This Standard:
will develop different strains with the same deflection. Also, pipes having
3.2.1 end point—the failure of the test specimen. The failure
the same wall thickness but different constructions making up the wall
mode may be catastrophic, characterized by a sudden fracture
may develop different strains with the same deflection.
through the pipe wall in the area of greatest strain.
3.2.2 fiberglass pipe—tubular product containing glass-fiber
6. Apparatus
reinforcements embedded in or surrounded by curing thermo-
6.1 Loading Device—The testing apparatus shall be suitable
for maintaining a constant load on the test specimen.
6.2 Load Application—The load may be applied to the test
This test method is under the jurisdiction of ASTM Committee D-20 on Plastics
and is the direct responsibility of Subcommittee D20.23 on Reinforced Plastic
specimens using any of three alternative pairs of parallel
Piping Systems and Chemical Equipment.
loading surfaces; flat plates, rods or bars of a length at least as
Current edition approved July 10, 1999. Published September 1999. Originally
long as the pipe ring and of sufficient strength and stiffness to
published as D 5365 - 93. Last previous edition D 5365 - 93.
Annual Book of ASTM Standards, Vol 08.01.
ensure a straight loading surface throughout the test. The same
Annual Book of ASTM Standards, Vol 08.04.
Copyright © ASTM, 100 Barr Harbor Drive, West Conshohocken, PA 19428-2959, United States.
D 5365
type of loading device shall be used for each specimen in a test
series. In order to achieve uniform strain along the pipe, use
0.25-in. (6-mm) thick elastomeric pads between the parallel
loading surfaces and the pipe ring (see Note 2).
6.2.1 Flat Plates—The plates shall have a minimum 6-in.
(152-mm) width.
6.2.2 Bars—The bars shall have a flat contact surface of
0.75 6 0.25 in. (19 6 6 mm).
6.2.3 Rods—The rod diameter shall be 2 6 0.25 in. (51 6
6 mm) for pipe rings 12 in. (305 mm) and greater in diameter.
For smaller pipes, the rod diameter shall be 1 6 0.25 in. (25 6
6 mm).
Side View Front View
6.3 Environment Containment—A test enclosure of suffi-
1 Load-Application Guides 5 Submerged Test Specimen
cient size to fully immerse the test specimens shall be used to
2 Load-Application Device 6 Test Solution
3 0.25 in (6 mm) Rubber Pad 7 0.25 in. (6 mm) Rubber Pad
contain the test solution. The enclosure shall not chemically
4 Test Enclosure 8 Load-Applicatiion Device
affect the test solution.
NOTE 4—Elastomeric pads with a hardness of Shore A 40 to 70 have
FIG. 1 Long-Term Ring Bending Test Apparatus
been used successfully.
by subtracting the average vertical inside diameter after load-
7. Test Specimens
ing from the measurement determined in 9.1.2.
7.1 The test specimens shall be ring sections taken from
NOTE 7—Deflections in excess of 28 % of diameter may cause local
sample(s) of pipe selected at random from a normal production
flattening of the pipe and lead to erratic test results. For deflections
run. The test specimens shall have a minimum length of one
approaching 28 %, improved accuracy is obtained by use of strain gages
nominal pipe diameter or 12 in. (305 mm), whichever is less
or by establishing, for each pipe product, a calibration of deflection versus
except for diameters over 60 in. (1524 mm) in that case, the
measured strain. This calibration technique may also be useful at all
specimen width shall be 20 % of the nominal diameter 6 1 in.
deflection levels.
(25 mm). Treat the cut edges of the specimens by the same
9.5 Introduce the test solution to completely submerge the
procedure as production products.
pipe ring. The solution may be added prior to loading the pipe
ring and should be added within 30 min of loading the pipe
8. Test Conditions
ring. Testing time commences only after both specimen loading
8.1 The standard temperature shall be 23 6 5°C (73.4 6
(deflection) and the addition of solution are complete.
9°F).
NOTE 8—Caution: Since the failure mode could be catastrophic, take
9. Procedure
precautions to prevent or contain splashing or spilling of the test solution
or other damages resulting from the sudden collapse of the pipe specimen.
9.1 Test Specimen Measurements:
9.1.1 Wall Thickness—Determine in accordance with Test
9.6 Periodically check and maintain the test solution within
Method D 3567.
65 % of the specified strength or concentration for the
9.1.2 Inside Diameter—Determine in accordance with Test
duration of the test. The test specimen must remain completely
Method D 3567 at both ends prior to deflection and average the
submerged.
measurements.
NOTE 9—As some solutions become more concentrated with the
evaporation of water, care must be exercised in replenishment to prevent
NOTE 5—It is recommended that the inside diameter be measured with
a build-up in strength. It may be necessary, with some reagents, to
the axis vertical.
periodically clean the deflected specimen and replace the test solution with
9.2 Place the test apparatus into the test enclosure.
a fresh mixture. The use of plastic film, cut carefully to fit around the test
9.3 Place the pipe ring in the test apparatus (see Fig. 1) and
apparatus and floated on the top of the test solution, has been found
apply force to deflect the specimen at a rate not to exceed 10 %
helpful in reducing evaporation.
of its diameter per minute while keeping the top and bottom
9.7 Continuously monitor the decreasing pipe-ring inside
loading devices (plates, bars, or rods) of the apparatus as near
vertical diameter versus time or inspect the loaded specimen at
parallel as practical. When the desired deflection is obtained
least at the frequency given below and measure the pipe
cease adding load to the apparatus.
specimen inside vertical diameter:
NOTE 6—Alignment of the specimen within the loading devices is
Hours Inspect at Least
critical. The loading devices should not only be parallel with the load 0 to 20 Every hour
20 to 40 Every 2 h
points 180° opposite, but the pipe ring should also be centered between the
40 to 60 Every 4 h
load-application guides. Additionally, the load-application guides should
60 to 100 Every 8 h
permit complete vertical freedom of movement, so the specimen remains
100 to 600 Every 24 h
under constant load.
600 to 6000 Every 48 h
After 6000 Every week
9.4 Measure the vertical inside diameter of the deflected
pipe specimen at both ends to the nearest 0.01 in. (0.25 mm). Determine the deflection by subtracting the inside vertical
Average the measurements and determine the initial deflection diameter from the measurement determined in 9.1.2.
D 5365
NOTE 10—Decreasing diameter of the pipe ring (deflection change)
10.2.2 Use for each specimen in the series, the log of the
may be monitored with an appropriate indicator on the apparatus above
failure strain and the log of the failure time in hours as
the solution and submerged specimen.
described in A1.4.1. Calculate S , the strain at 50 years
b
(438 000 h).
9.8 Calculate the end point (failure time and failure deflec-
10.2.3 If Sxy > 0 (see Annex A1.4.2.2), consider the data
tion) in accordance with 10.1.
unsuitable.
9.9 Record the following data:
10.2.4 Calculate r in accordance with A1.4.3.1. If r is less
9.9.1 Average pipe-wall thickness,
than the applicable minimum value given in Table A1.1,
9.9.2 Average inside pipe diameter before deflection,
consider the data unsuitable.
9.9.3 Average inside pipe diameter after deflection,
10.2.5 Prepare a graph on a log-log diagram showing time
9.9.4 Initial deflection,
to failure versus failure strain, with time plotted on the
9.9.5 Type of loading device,
horizontal (x) axis and strain on the vertical ( y) axis.
9.9.6 Type, location and time of any distress of the pipe
wall,
11. Reconfirmation of the S Regression Line
b
9.9.7 Failure deflection and time at the end point, and
11.1 When a piping product has an existing S regression
b
9.9.8 Type of failure.
line, any change in material, manufacturing process, construc-
9.10 To determine the regression line and the lower confi-
tion or liner will necessitate a screening evaluation as described
dence level, a minimum of 18 samples is required. Distribution
in 11.2, 11.3, 11.4, 11.5, and 11.6.
of data points shall be as follows:
11.2 Obtain failure points for at least two sets of specimens.
Hours Failure Points
Each specimen set shall consist of three or more specimens
10 to 1000 At least 4
1000 to 6000 At least 3 tested at the same initial strain level, as follows:
After 6000 At least 3
Hours to Failure Failure Points
After 10 000 At least 1
(Average of Set)
10 to 200 At least 3
9.10.1 Those specimens that have not failed after more than
More than 1000 At least 3
10 000 h may be included as failures to establish the regression
Total: At least 6
line. Use of these data points may result in a higher or lower
Include as failures those specimens that have not failed after
extrapolated value.
3000 h, provided they exceed the regression line.
NOTE 11—Non-failed specimens may be left under test and the regres-
11.3 Calculate and plot the 95 % confidence limits and the
sion line recalculated as failures are obtained.
95 % prediction limits of the original regression line in
accordance with A1.4.6.2 using only data obtained prior to the
10. Calculation
change.
10.1 Determine the failure time and deflection:
NOTE 13—Prediction limits define the bounds for single observations,
10.1.1 The failure deflection and failure time shall be the
whereas confidence limits define the bounds for the regression line.
last values noted prior to the fracture occurrence.
NOTE 14—For 95 % confidence limits, there is a 2.5 % probability that
10.2 Long-Term Ring-Bending Strain:
the mean value for the regression line may fall above the UCL and a 2.5 %
10.2.1 Compute the failure strain for each failed specimen
probability that the mean value for the regression line may fall below the
as given in 10.2.1.1 and 10.2.1.2. LCL. For 95 % prediction limits, there is a 2.5 % probability that
individual data points may fall above the UPL and a 2.5 % probability that
10.2.1.1 Crown and invert failures:
individual data points may fall below the LPL.
4.28 e D
~ !~ !
f
e 5
11.4 Consider any changes in material or manufacturing
f 2
~D1D /2!
f
process minor and permissible if the results of 11.2 meet the
following criteria:
where:
e = failure strain in inches per inch (millimetres per 11.4.1 The average failure point for each specimen set falls
f
millimetre), on or above the 95 % lower confidence limit of the original
e = wall thickness in inches (millimetres) in accordance
regression line.
with 9.1.1 (see Note 12), 11.4.2 The earliest individual failure point falls on or above
D = mean diameter in inches (millimetres) (ID in accor-
the 95 % lower-prediction limit of the original regression line.
dance with 9.1.2 plus e in accordance with 9.1.1 or
11.4.3 The failure points are distributed about the originally
OD minus e), and
determined regression line. No more than two-thirds of the
D = failure deflection in accordance with 10.1.
f individual failure points may fall below the original regression
10.2.1.2 Springline failures:
line.
11.5 Alternatively to 11.4, consider changes in material or
2.44~e!~D !
f
e 5
f 2
manufacturing process permissible if the results of 11.2 meet
~D1D /2!
f
the following:
N
...
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