1、Designation: F 112 00 (Reapproved 2006)Standard Test Method forSealability of Enveloped Gaskets1This standard is issued under the fixed designation F 112; the number immediately following the designation indicates the year oforiginal adoption or, in the case of revision, the year of last revision. A
2、 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 covers the evaluation of the sealingproperties of enveloped gaskets for use with corrosion-resistantprocess equipmen
3、t.2Enveloped gaskets are described as gas-kets having some corrosion-resistant covering over the internalarea normally exposed to the corrosive environment. Theshield material may be plastic (such as polytetrafluoroethylene)or metal (such as tantalum). A resilient conformable filler isusually used i
4、nside the envelope. The design and constructionof nonmetallic gaskets is covered in Practice F 336.1.2 The values stated in SI units are to be regarded as thestandard. The values given in parentheses are for informationonly.1.3 This standard does not purport to address all of thesafety concerns, if
5、any, associated with its use. It is theresponsibility of the user of this standard to establish appro-priate safety and health practices and determine the applica-bility of regulatory limitations prior to use. For specificprecautionary statements, see Section 6.2. Referenced Documents2.1 ASTM Standa
6、rds:3F37 Test Methods for Sealability of Gasket MaterialsF 336 Practice for Design and Construction of NonmetallicEnveloped Gaskets for Corrosive Service2.2 ASTM Adjuncts:Detailed Drawing of Test Fixture43. Summary of Method3.1 An enveloped gasket is compressed between two boltedflanges in a special
7、 test fixture.5After the specified load isapplied to the gasket, air at the specified pressure is introducedinto the test chamber and then the test chamber is sealed.Pressure and temperature readings are taken and recorded atspecified intervals. The leakage rate is measured by the changein the test
8、chamber pressure over time. The flange load on thegasket is increased and the process is repeated.3.2 Results of the sealability test are expressed as a graph ofthe remaining test chamber pressure versus time for thespecified conditions.4. Significance and Use4.1 This test method is designed to eval
9、uate all types ofenveloped gaskets under controlled conditions with respect toleakage and to provide measurable leakage rates.4.2 Determining torque required to seal a given gasket isalso part of this test method. By converting the torque atsealing to total bolt load, useful design information may b
10、eobtained for other standard and nonstandard openings.4.3 This test method may be used as an incoming qualitycontrol test to evaluate similar gaskets from different suppliers.This test method may also be used as a quality control testwhen parameters are agreed upon between the producer and theuser.4
11、.4 Leakage through the gasket or over the gasket, or both,is determined by this test method.5. Apparatus5.1 Leakage Test UnitThe unit5shall contain a suitablepressure gauge to read from 0 to 2.1 MPa (0 to 300 psig) andmounted as shown in Fig. 1.5.2 Compressed Air Supply, capable of supplying 621 kPa
12、(90 psig) to the test unit.1This test method is under the jurisdiction of ASTM Committee F03 on Gasketsand is the direct responsibility of Subcommittee F03.10 on Composite Gaskets.Current edition approved Oct. 1, 2006. Published December 2006. Originallyapproved in 1970. Last previous edition approv
13、ed in 2000 as F 112 00e1.2This test method is to be used in place of Test Methods F37, which apply onlyto single-component gasket materials and are not applicable to envelope-stylegaskets. This fixture may also be used for other gasket materials or designs, with orwithout modification.Supporting dat
14、a have been filed atASTM International Headquarters and may beobtained by requesting Research Report RR: F03-1000.3For referenced ASTM standards, visit the ASTM website, www.astm.org, orcontact ASTM Customer Service at serviceastm.org. For Annual Book of ASTMStandards volume information, refer to th
15、e standards Document Summary page onthe ASTM website.4Available from ASTM International Headquarters. Order Adjunct No.ADJF0112. Original adjunct produced in 1970.5The sole source of supply of the apparatus known to the committee at this timeis Pfaudler Co., 1000 West Ave., Rochester, NY 14603. If y
16、ou are aware ofalternative suppliers, please provide this information to ASTM InternationalHeadquarters. Your comments will receive careful consideration at a meeting of theresponsible technical committee,1which you may attend.1Copyright ASTM International, 100 Barr Harbor Drive, PO Box C700, West C
17、onshohocken, PA 19428-2959, United States.5.3 Temperature Indicating DeviceA thermometer ca-pable of reading in increments of 1C in the ambient tempera-ture range.6. Hazards6.1 Use only a unit suitable for a minimum of 1034 kPa(150 psig).6.2 A metal shield box with access doors is suggested as anadd
18、ed safety factor.6.3 Prior to performing any tests, inspect the unit fordamage, corrosion, and also for metal fatigue cracks that mayhave developed.7. Test Specimen7.1 Commercial 102-mm (4-in.) nominal size envelopedgasket with a shield 102 mm (4 in.) in inside diameter(minimum) and inserts 114 mm (
19、4.5 in.) in inside diameter by175 mm (6.88 in.) in outside diameter. The thickness of the testgasket will depend upon its expected usage and must bespecified in the report as results will vary accordingly.8. Conditioning8.1 Conditioning of the test gasket is not necessary sincethis test method is de
20、signed for shelf stock. Assembledenveloped gaskets and the components used in their construc-tion would not be affected by aging under normal storageconditions.9. Procedure9.1 The temperature for this test is normally ambient roomtemperature.9.2 Assemble the gasket in the test unit.9.3 Lubricate the
21、 bolt threads well using molydisulfide dryfilm or grease. Sanding the bottom of the bolt heads and thewashers will minimize torque variables and ensure duplicationof results.9.4 Gradually and evenly tighten the bolts to 39 Nm (29lbfft) following the sequence indicated by the numbers in Fig.2. Progre
22、ssion of the tightening on each bolt should be inapproximately 7-Nm (5-lbfft) increments.9.5 Apply 621 kPa (90 psig) of air pressure into the test unitand seal. Record the pressure readings every hour for4handthen at the end of 20 h, but since the readings are temperaturedependent, take and record t
23、he temperature within the oil-filledthermowell to coincide with the time of the pressure readings.Apply corrections if required.9.6 Fill the test fixture thermowell three-quarters full with alight oil.6Allow 15 minutes for the temperature to stabilize,and insert the temperature sensor.9.7 Retighten
24、the bolts to 57 Nm (42 lbfft) in accordancewith 9.4 and proceed as in 9.5.9.8 Continue testing using bolt tensions of 85 Nm (63lbfft), 102 Nm (75 lbfft), and 122 Nm (90 lbfft) inaccordance with 9.4 and proceed as in 9.5.9.9 Repeat 9.2-9.8 using another gasket from the same lot.10. Report10.1 Report
25、the following information:10.1.1 Identification of the enveloped gasket,10.1.2 Gasket thickness,10.1.3 Pressure readings versus time, and10.1.4 Plot of remaining pressure versus time, h, for eachtorque level.11. Precision and Bias11.1 Precision:6Mineral oil or commercially available heat transfer oi
26、l has been foundsatisfactory.FIG. 1 Test UnitNOTETighten bolts evenly; follow numerical sequence.FIG. 2 Bolt Tightening ProgressionF 112 00 (2006)211.1.1 The condition and the lubrication of the bolts have adirect bearing on the precision and bias of this test method.11.1.2 A variation of 5 % betwee
27、n laboratories may beexpected using this procedure.11.2 Biassince there is no accepted reference materialsuitable for determining the bias of the procedure in this testmethod for measuring sealability of gasket materials, nostatement on bias is available.12. Keywords12.1 enveloped gaskets; metal; PT
28、FE; sealabilityAPPENDIX(Nonmandatory Information)X1. TYPICAL EXAMPLES OF RECORDING AND PLOTTINGENVELOPED GASKET SEALABILITY TEST DATAX1.1 Example 1X1.1.1 A typical PTFE (polytetrafluoroethylene) envelopedgasket might give the pressure readings shown in Fig. X1.1 andTable X1.1.X1.1.2 Interpretation o
29、f ResultsA slight leakage wasobtained at 39 and 57 Nm (29 and 42 lbfft) torque. Completesealing was attained at the 85 Nm (63 lbfft) torque compres-sion. By converting the torque at sealing to total bolt load,useful design information may be obtained for other standardor nonstandard openings.X1.2 Ex
30、ample 2X1.2.1 A typical metal enveloped gasket might give thepressure readings shown in Fig. X1.2 and Table X1.2.X1.2.2 Interpretation of ResultsThe results indicate that122 Nm (90 lbfft) torque is required to seal this particularmetal shielded gasket against an internal pressure of 621 kPa(90 psi).
31、 This information may be used to check the adequacyof other standard opening sizes or to properly design nonstand-ard joints where this type of gasket is to be used.FIG. X1.1 Pressure Reading Plot for PTFE Enveloped GasketsF 112 00 (2006)3ASTM International takes no position respecting the validity
32、of any patent rights asserted in connection with any 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 t
33、o revision at any time by the responsible technical 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.
34、 Your comments will receive careful consideration at 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
35、copyrighted by ASTM International, 100 Barr Harbor 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 serviceast
36、m.org (e-mail); or through the ASTM website(www.astm.org).TABLE X1.1 Pressure Readings for Typical PTFE Enveloped GasketATorque Original Pressure 1 h 2 h 3 h 4 h 20 hNm (lbfft) kPa (psi) kPa (psi) kPa (psi) kPa (psi) kPa (psi) kPa (psi)39 (29) 621 (90) 621 (90) 614 (89) 614 (89) 614 (89) 586 (85)57
37、(42) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90) 607 (88)85 (63) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90)102 (75) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90)122 (90) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90)AThese figures would be plotted as shown in Fig. X1.1.FIG
38、. X1.2 Pressure Reading Plot for Metal Enveloped GasketsTABLE X1.2 Pressure Readings for Typical Metal Enveloped GasketATorque Original Pressure 1 h 2 h 3 h 4 h 20 hNm (lbfft) kPa (psi) kPa (psi) kPa (psi) kPa (psi) kPa (psi) kPa (psi)39 (29) 621 (90) 393 (57) 276 (40) 207 (30) 152 (22) 0 (0)57 (42)
39、 621 (90) 565 (82) 531 (77) 510 (74) 469 (68) 214 (31)85 (63) 621 (90) 621 (90) 607 (88) 600 (87) 586 (85) 441 (64)102 (75) 621 (90) 621 (90) 621 (90) 621 (90) 614 (89) 558 (81)122 (90) 621 (90) 621 (90) 621 (90) 621 (90) 621 (90) 600 (87)AThese figures would be plotted as shown in Fig. X1.2.F 112 00 (2006)4
