ASTM F725-03(2008)e1
(Practice)Standard Practice for Drafting Impact Test Requirements In Thermoplastic Pipe And Fittings Standards
Standard Practice for Drafting Impact Test Requirements In Thermoplastic Pipe And Fittings Standards
SIGNIFICANCE AND USE
This practice is used for drafting impact test specification requirements, and it presupposes no special familiarity with statistical methods. It provides for specification values that will pass acceptable lots with a high degree of certainty. The impact test requirement is intended to discriminate between acceptable materials and manufacturing methods and those which are not; it is not a simulated service test.
SCOPE
1.1 This practice describes a procedure for setting up impact test requirements on the basis of test data obtained by Test Method D 2444.
1.2 This practice is applicable to thermoplastic pipe and fittings.
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.
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´1
Designation: F725 − 03(Reapproved 2008) An American National Standard
Standard Practice for
Drafting Impact Test Requirements In Thermoplastic Pipe
And Fittings Standards
ThisstandardisissuedunderthefixeddesignationF725;thenumberimmediatelyfollowingthedesignationindicatestheyearoforiginal
adoptionor,inthecaseofrevision,theyearoflastrevision.Anumberinparenthesesindicatestheyearoflastreapproval.Asuperscript
epsilon (´) indicates an editorial change since the last revision or reapproval.
ε NOTE—Section X1.1 was editorially revised in March 2008.
1. Scope 3.1.3 mean strength—theaveragestrengthofthetotalpopu-
lation (see Note 2).
1.1 Thispracticedescribesaprocedureforsettingupimpact
3.1.4 OC curve (operating characteristic curve)— a graph
test requirements on the basis of test data obtained by Test
that illustrates the chance of success or failure when a given
Method D2444.
specification format is employed, given any quality level from
1.2 This practice is applicable to thermoplastic pipe and
0to1(0to100%passinginthelotfromwhichtestspecimens
fittings.
are selected).
1.3 This standard does not purport to address all of the
3.1.5 probability graph paper—commercially available
safety concerns, if any, associated with its use. It is the
graph paper that provides straight-line plots when the distribu-
responsibility of the user of this standard to establish appro-
tion of attributes is normal. For a discussion on the use of
priate safety and health practices and determine the applica-
proability graph paper, see Test Method D2444 Appendix X2.
bility of regulatory limitations prior to use.
3.1.6 specification format—the rules set forth by the test
requirement, including the number of specimens to be tested
2. Referenced Documents
and the minimum acceptable number of passes.
2.1 ASTM Standards:
3.1.7 standard deviation—a statistical term that relates to
D2444Test Method for Determination of the Impact Resis-
the size of the expected variation in test results.
tance of Thermoplastic Pipe and Fittings by Means of a
Tup (Falling Weight)
NOTE 2—The terms “mean,” “normal distribution,” and “standard
deviation” are dealt with in elementary statistics textbooks.
3. Terminology
4. Summary of Practice
3.1 Definitions of Terms Specific to This Standard:
4.1 Round-robin tests of representative pipe and fittings
3.1.1 binomial probability equation—the equation that de-
specimens are performed to identify the energy levels at which
fines the chance for exactly r specimens to pass, when n are
90% or more of the specimens in acceptable lots will pass.A
tested, given p, the chance that a single specimen chosen at
preferred test format is listed. The B-tup and the V-block
random will pass. It is expressed as follows:
holder, and room-temperature conditioning and tests are pre-
n!
r n2r ferred choices.
P 5 p 1 2 p (1)
~ !
r n
r! n 2 r !
~ !
NOTE 1—The factorial of zero is one.
5. Significance and Use
3.1.2 binomial test—a test that has only two possible results
5.1 This practice is used for drafting impact test specifica-
(for example, pass or fail, heads or tails, true or false).
tion requirements, and it presupposes no special familiarity
with statistical methods. It provides for specification values
that will pass acceptable lots with a high degree of certainty.
This practice is under the jurisdiction of ASTM Committee F17 on Plastic
The impact test requirement is intended to discriminate be-
Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test
tween acceptable materials and manufacturing methods and
Methods.
those which are not; it is not a simulated service test.
Current edition approved March 1, 2008. Published April 2008. Originally
ε1
approved in 1981. Last previous edition approved in 2003 as F725–03 . DOI:
6. Procedure
10.1520/F0725-03R08E01.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or
6.1 Test thermoplastic pipe or fittings specimens in accor-
contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
dance with Test Method D2444, and plot the test results on
Standards volume information, refer to the standard’s Document Summary page on
the ASTM website. probability graph paper.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
´1
F725 − 03 (2008)
6.2 It will be clear, from the probability paper plot, that the
energy level where 98% or 99% of all specimens would pass
willbelow.Ontheonehand,whenthetestformatrequiresthat
five of five, or six of six, or nine or ten of ten tested shall pass,
or the lot rejected, then the specified energy levels must
correspond to these levels (see Fig. 1, the operating character-
istic(OC)curveforthe“nineortenoften”testformat).Onthe
other hand, five of five, six of six, and nine or ten of ten tests
at low energy levels will not screen marginal or poor lots
effectively. (See Fig. 1 again).
6.3 Aformat which will accept reliably when 90% or more
of the specimens in acceptable lots would pass, and reject
reliably when 60% or fewer would pass, is as follows:
6.3.1 “X.X Test ten specimens. When nine or ten pass,
accept the lot. When six or fewer pass, reject the lot. When
seven or eight pass, test ten additional specimens. When 17 or
more of 20 pass, accept the lot. When 13 or fewer of 20 pass,
reject the lot. When 14, 15, or 16 pass, test 20 additional
FIG. 2 O.C. Curve for Section 6.3
specimens. When 32 or more of 40 pass, accept the lot. When
31 or fewer pass, reject the lot.”
6.3.2 The OC curve for this format is illustrated in Fig. 2.
choice (study Fig. 1 together with a data plot performed in
6.4 Specimen Length—The pipe specimen length should be accordance with Test Method D2444 to fully grasp the merits
6 in. (150 mm) 6 ⁄4 in. (6mm). of this statement).
6.5 Choice of Tup and Holder—The B tup is preferred. It
7. Multiple-Product Standards
provides a good compromise between energy concentration in
7.1 Many thermoplastic pipe and fittings specifications list
the specimen (and therefore reduced test energy levels), and
large numbers of products.Test Method D2444 requires that at
resistance to damage in service. The V-block holder is pre-
least 100 test specimens shall be employed for each single test
ferred for pipe specimens; it provides for greater energy
run in order that the impact properties can be measured with
concentration, and for failures in a range of thin-walled
useful accuracy. The cost of round-robin tests on each size of
specimens which would merely flatten on the flat-plate holder.
the products in the standard may approach or exceed the value
6.6 Test Conditions—Room-temperature tests are preferred.
of the information to be obtained.
They can be performed by the manufacturer on a timely basis,
7.2 Testingcostscanbesignificantlyreducedbyperforming
so that the size of questionable or defective inventories is
preliminary tests on the largest sizes listed, to determine
minimized. Binomial tests are relatively crude, unless large
whetherornotacut-offpointexistsabovewhichallspecimens
numbers of specimens are subjected to test. The expense and
will pass at an energy level of 300 ft·lbf (407 J) (ordinarily the
inconvenienceoflow-temperatureconditioningrenderitapoor
highest test energy level listed in a t
...
This document is not anASTM standard and is intended only to provide the user of anASTM 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.
An American National Standard
e1
Designation:F 725–89(Reapproved 1996) Designation: F 725 – 03 (Reapproved 2008)
Standard Practice for
Drafting Impact Test Requirements In Thermoplastic Pipe
And Fittings Standards
This standard is issued under the fixed designation F 725; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (e) indicates an editorial change since the last revision or reapproval.
e NOTE—Section X1.1 was editorially revised in March 2008.
1. Scope
1.1 ThispracticedescribesaprocedureforsettingupimpacttestrequirementsonthebasisoftestdataobtainedbyTestMethod
D2444.
1.2 This practice is applicable to thermoplastic pipe and fittings.
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.
2. Referenced Documents
2.1 ASTM Standards:
D2444 TestMethodforDeterminationoftheImpactResistanceofThermoplasticPipeandFittingsbyMeansofaTup(Falling
Weight)
3. Terminology
3.1 Definitions of Terms Specific to This Standard:
3.1.1 binomial probability equation—the equation that defines the chance for exactly r specimens to pass, when n are tested,
given p, the chance that a single specimen chosen at random will pass. It is expressed as follows:
n!
r n2r
P 5 p ~1 2 p! (1)
r n
r!~n–r!!
NOTE 1—The factorial of zero is one.
3.1.2 binomial test—a test that has only two possible results (for example, pass or fail, heads or tails, true or false).
3.1.3 mean strength—the average strength of the total population (see Note 2).
3.1.4 OC curve (operating characteristic curve)— a graph that illustrates the chance of success or failure when a given
specification format is employed, given any quality level from 0 to 1 (0 to 100% passing in the lot from which test specimens
are selected).
3.1.5 probability graph paper—commercially available graph paper that provides straight-line plots when the distribution of
attributes is normal. —commercially available graph paper that provides straight-line plots when the distribution of attributes is
normal. For a discussion on the use of proability graph paper, see Test Method D 2444 Appendix X2.
3.1.6 specification format—the rules set forth by the test requirement, including the number of specimens to be tested and the
minimum acceptable number of passes.
3.1.7 standard deviation—a statistical term that relates to the size of the expected variation in test results.
NOTE 2—The terms “mean,” “normal distribution,” and “standard deviation” are dealt with in elementary statistics textbooks.
This practice is under the jurisdiction of ASTM Committee F-17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test Methods.
Current edition approved Dec. 29, 1989. Published February 1990. Originally published as F725–81. Last previous edition F725–81.
This practice is under the jurisdiction of ASTM Committee F17 on Plastic Piping Systems and is the direct responsibility of Subcommittee F17.40 on Test Methods.
e1
Current edition approved March 1, 2008. Published April 2008. Originally approved in 1981. Last previous edition approved in 2003 as F725–03 .
Annual Book of ASTM Standards, Vol 08.04.
ForreferencedASTMstandards,visittheASTMwebsite,www.astm.org,orcontactASTMCustomerServiceatservice@astm.org.For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
e1
F 725 – 03 (2008)
4. Summary of Practice
4.1 Round-robin tests of representative pipe and fittings specimens are performed to identify the energy levels at which 90%
or more of the specimens in acceptable lots will pass. A preferred test format is listed. The B-tup and the V-block holder, and
room-temperature conditioning and tests are preferred choices.
5. Significance and Use
5.1 This practice is used for drafting impact test specification requirements, and it presupposes no special familiarity with
statistical methods. It provides for specification values that will pass acceptable lots with a high degree of certainty. The impact
test requirement is intended to discriminate between acceptable materials and manufacturing methods and those which are not; it
is not a simulated service test.
6. Procedure
6.1 TestthermoplasticpipeorfittingsspecimensinaccordancewithTestMethodD2444,andplotthetestresultsonprobability
graph paper.
6.2 It will be clear, from the usualprobability paper plot, that the energy level where 98% or 99% of all specimens would pass
will be low. On the one hand, when the test format requires that five of five, or six of six, or nine or ten of ten tested shall pass,
or the lot rejected, then the specified energy levels must correspond to these levels (see Fig. 1, the operating characteristic (OC)
curve for the “nine or ten of ten” test format). On the other hand, five of five, six of six, and nine or ten of ten tests at low energy
levels will not screen marginal or poor lots effectively. (sSee Fig. 1 again).
6.3 Aformat which will accept reliably when 90% or more of the specimens in acceptable lots would pass, and reject reliably
when 60% or fewer would pass, is as follows:
6.3.1 “X.X Test ten specimens. When nine or ten pass, accept the lot. When six or fewer pass, reject the lot. When seven or
eight pass, test ten additional specimens. When 17 or more of 20 pass, accept the lot. When 13 or fewer of 20 pass, reject the lot.
When 14, 15, or 16 pass, test 20 additional specimens. When 32 or more of 40 pass, accept the lot. When 31 or fewer pass, reject
the lot.”
6.3.2 The OC curve for this format is illustrated in Fig. 2.
6.4 Specimen Length—The pipe specimen length should be 6 in. (150 mm) 6 ⁄4 in. (6mm).
6.5 Choice of Tup and Holder—The B tup is preferred. It provides a good compromise between energy concentration in the
specimen (and therefore reduced test energy levels), and resistance to damage in service. The V-block holder is preferred for pipe
specimens; it provides for greater energy concentration, and for failures in a range of thin-walled specimens which would merely
flatten on the flat-plate holder.
6.6 Test Conditions—Room-temperature tests are preferred. They can be performed by the manufacturer on a timely basis, so
that the size of questionable or defective inventories is minimized. Binomial tests are relatively crude, unless large numbers of
specimens are subjected to test. The expense and inconvenience of low-temperature conditioning render it a poor choice (study
Fig. 1 together with a data plot performed in accordance with Test Method D2444to fully grasp the merits of this statement).
7. Multiple-Product Standards
7.1 Many thermoplastic pipe and fittings specifications list large numbers of products.Test Method D2444requires that at least
100 test specimens shall be employed for each single test run in order that the impact properties can be measured with useful
FIG. 1 O.C. Curve for Nine or Ten of Ten
e1
F 725 – 03 (2008)
FIG. 2 O.C. Curve for Section 6.3
accuracy. The cost of round-robin tests on each size of the products in the standard may approach or exceed the value of the
information to be obtained.
7.2 Testing costs can be significantly reduced by performing preliminary tests on the largest sizes listed, to determine whether
or not a cut-off point exists above which all specimens will pass at an energy level of 300 ft·lbf (407 J) (ordinaril
...
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