1、Designation: F 2331 04An American National StandardStandard Test Method forDetermining Chemical Compatibility of Thread Sealants withThermoplastic Threaded Pipe and Fittings Materials1This standard is issued under the fixed designation F 2331; the number immediately following the designation indicat
2、es the year oforiginal adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. Asuperscript epsilon (e) indicates an editorial change since the last revision or reapproval.1. Scope1.1 This test method is used for determining che
3、micalcompatibility of thread sealant compounds with threaded pipeand fittings materials. This procedure is generally applicable tothread sealant compounds which are either hard-cure, soft-cureor non-hardening paste at room temperatures (i.e. non-liquid orsemi-liquid).1.2 This standard does not purpo
4、rt to address all of thesafety concerns, if any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and to determine theapplicability of regulatory limitations prior to use.2. Referenced Documents2.1 ASTM Standards:2F 1
5、498 Specification for Taper Pipe Threads 60 for Ther-moplastic Pipe and FittingsD 638 Test Method for Tensile Properties of Plastics2.2 ASME Standards:B1.20.1 Pipe Threads, General Purpose (inch)3. Summary of Test Method3.1 The procedure uses tensile specimen test bars in alongitudinal tensile test
6、geometry in a constant load (creep)method. All procedures are run at an ambient temperature of73F (23C).4. Significance and Use4.1 These procedures can be used to evaluate thread sealantsrelative to causing environmental stress-cracking in thermo-plastic materials. This testing results in determinin
7、g time-to-failure vs. engineering stress. This procedure can also be usedin stress-rupture regression analysis, where a variety of stresslevels are needed. The methodology can be readily adapted toconducting immersion tests in liquids.5. Interferences5.1 In these procedures, there may be interferenc
8、e effectsdue to differences in resin or the additives in the thermoplasticmaterials. Until such time as data is available to address this,the user should take this into consideration when applying thistest method.6. Apparatus6.1 Apparatus for constant tensile method.6.1.1 Constant-tensile-load test
9、apparatus which maintainsthe load to within 61 % throughout the test duration.6.1.2 Immersion vessels which can be mounted to thetensile-load apparatus (if applicable).7. Test Specimen7.1 Test bars may be either fabricated from compressionmolded plaques or injection molded. Test times and/or stressl
10、evels may be reduced by incorporating a knit-line into aninjection-molded test bar. If a knit-line is present, the moldshould be designed such that the knit-line occurs in the centerof the bar, perpendicular to the longitudinal axis.7.2 AType IV specimen as shown in D 638 shall be used forreferee te
11、sting. Other specimen geometries may be used ifshown to provide equivalent results.8. Calibration and Standardization8.1 All test instrumentation shall be calibrated to standardstraceable to the National Institute of Standards and Technology.8.2 The test stress (tensile) shall be calibrated by use o
12、f aknown aggressive chemical agent (positive control) to deter-mine the stress needed to produce failures within 100 hours onat least 75 % of the specimens. This stress is then used fortesting of the thread sealant under consideration.NOTE 1The known aggressive chemical agent is generally deter-mine
13、d by causing premature failures as indicated in 9.2. Some agents maybe known from previous experience with the materials being used fortesting. For example, linseed and soybean oil have been used for thispurpose with PVC and CPVC test materials.1This test method is under the jurisdiction of ASTM Com
14、mittee F17 and is thedirect responsibility of Subcommittee F17.20 on Joining.Current edition approved May 1, 2004. Published June 2004 .2For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume in
15、formation, refer to the standards Document Summary page onthe ASTM website.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.8.2.1 A minimum of 4 specimens shall be tested for thepositive control.8.2.2 A minimum of 3 specimens shall be
16、 tested at the samestress or strain using a negative control agent (TFE-fluorocarbon pipe thread tape). The negative controls shall notfail after 1 000 hours.9. Conditioning9.1 Condition the specimens and the thread sealant for 40hours at 23 6 2C and 50 % 6 5 % RH prior to applying thesealant to the
17、 specimen.10. Procedure10.1 Constant tensile method10.1.1 Attach the grips to the test specimen. The ends of thegrips shall be at least 0.75 inch (15 mm) from the area wherethe test sealant is being applied. If testing in an immersionapparatus, this requirement does not apply, but care must betaken
18、to ensure failures are not initiated in the region near thegrips.10.1.2 If using a semi-solid paste sealant, wrap the speci-mens with plastic wrap or aluminum foil to prevent evapora-tion of liquid components of the paste.10.1.3 Apply the load to the specimen gradually within aperiod of 5 to 10 seco
19、nds without any abrupt or impact-typeloading of the specimen.10.1.4 Record the time-to-failure of each specimen.10.1.5 If the failure occurs at an area away from where thesealant was applied (i.e. clean tensile bar region), at a time lessthan the negative control, it shall not be considered a valid
20、testfor that specimen. If only one of 4 specimens fails in thismanner, it may be discarded and the remaining three reported.If more than one fails in this manner, new specimens shall betested.11. Calculation or Interpretation of Results11.1 For this method, the applied stress or strain should besuff
21、icient to cause failures with known stress-cracking agentswithin 100 hours.As such, it is generally considered acceptableif the sealant under test does not cause a failure within 1 000hours at that same stress level.12. Report12.1 Complete identification of the sealant tested, plasticmaterial used f
22、or the test bars, positive control substance andnegative control substance (if any). This information shallinclude manufacturer, trade designations, principle dimensionsand material identification code or designation.12.2 Method of preparing test specimens.12.3 Environment during conditioning and te
23、sting.12.4 Conditioning procedure (time/temp/RH)12.5 Number of specimens tested12.6 Cross-sectional dimensions of test specimens12.7 Stress levels used in testing.12.8 Torque applied if using Procedure A12.9 Results of positive control12.10 Results of negative control12.11 Date of test12.12 Referenc
24、e to this test method F 2331 and the proce-dure used.13. Precision and Bias13.1 This test method specifies a result that is a nonnumeri-cal report of success or failure categorized based on criteriaspecified in the procedure (positive and negative controls). Assuch, no information is presented about
25、 either the precision orbias of Test Method F 2331 for measuring chemical compat-ibility of thread sealants.14. Keywords14.1 Thread sealant; chemical compatibility; ABS; PVC;CPVC; fittingsASTM International takes no position respecting the validity of any patent rights asserted in connection with an
26、y item mentionedin this standard. Users of this standard are expressly advised that determination of the validity of any such patent rights, and the riskof infringement of such rights, are entirely their own responsibility.This standard is subject to revision at any time by the responsible technical
27、 committee and must be reviewed every five years andif not revised, either reapproved or withdrawn. Your comments are invited either for revision of this standard or for additional standardsand should be addressed to ASTM International Headquarters. Your comments will receive careful consideration a
28、t a meeting of theresponsible technical committee, which you may attend. If you feel that your comments have not received a fair hearing you shouldmake your views known to the ASTM Committee on Standards, at the address shown below.This standard is copyrighted by ASTM International, 100 Barr Harbor
29、Drive, PO Box C700, West Conshohocken, PA 19428-2959,United States. Individual reprints (single or multiple copies) of this standard may be obtained by contacting ASTM at the aboveaddress or at 610-832-9585 (phone), 610-832-9555 (fax), or serviceastm.org (e-mail); or through the ASTM website(www.astm.org).F2331042
