1、Designation:D721113(Reapproved 2018)Standard Specification forParts Machined from Polychlorotrifluoroethylene(PCTFE)and Intended for General Use1This standard is issued under the fixed designation D7211;the number immediately following the designation indicates the year oforiginal adoption or,in the
2、 case of revision,the year of last revision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.1.Scope1.1 This specification is intended to be a means of callingout finished machined parts ready for
3、commercial use.1.2 This specification establishes requirements for partsmachined from unplasticized,100%polychlorotrifluoroethyl-ene(PCTFE)homopolymers.1.3 This specification does not cover parts machined fromPCTFE copolymers,PCTFE film or tape less than 0.25-mm(0.010-in.)thick,or modified PCTFE(con
4、taining pigments orplasticizers).1.4 This specification allows for parts containing regrindand recycled material.1.5 The specification does not cover PCTFE parts used inaerospace applications involving storage and handling ofoxygen media,air media,inert media,and certain reactivemedia(specifically a
5、mmonia,gaseous hydrogen,and liquidhydrogen),in which dimensional stability,high molecularweight,molecular weight retention,and crystallinity controlare important considerations.For aerospace grade,machinedPCTFE parts,use Specification D7194.1.6 ApplicationPCTFE parts covered by this specificationare
6、 made of 100%PCTFE resin,free of plasticizers,fillers,orother additives.The parts meet specific physical characteristicsappropriate for their end use,and are typically used inapplications requiring good electrical properties or resistanceto aggressive chemical media.General purpose PCTFE partsinclud
7、e seals,gaskets,valve and pump parts(cryogenic andnoncryogenic),translucent tubing,sight glasses,flowmetertubes,heavy-walled solid pipes and fittings,gears,cams,bearings,laboratory ware,circuit boards,electrical connectorcovers and switches,radome covers,and a variety of otherstock shapes.They are r
8、emoved and replaced during normalmaintenance procedures.The parts also experience static ordynamic mechanical loading,and temperatures ranging fromcryogenic to temperatures at or above the glass transitiontemperature,Tg=55C(131F).NOTE1Quick-quenched PCTFE will potentially exhibit dimensionalrelaxati
9、on in the vicinity of Tg.NOTE2Although no recommendations are made regarding the limit-ing upper use temperature of PCTFE,the heat deflection temperature ofPCTFE as determined by Test Method D648 is 126C(259F).1.7 The values stated in SI units are to be regarded asstandard.The values in parentheses
10、are for information only.1.8 The following precautionary caveat pertains only to thetest methods portion,Section 11,of this specification:Thisstandard does not purport to address all of the safety concerns,if any,associated with its use.It is the responsibility of the userof this standard to establi
11、sh appropriate safety,health,andenvironmental practices and determine the applicability ofregulatory limitations prior to use.NOTE3There is no known ISO equivalent to this standard.1.9 This international standard was developed in accor-dance with internationally recognized principles on standard-iza
12、tion established in the Decision on Principles for theDevelopment of International Standards,Guides and Recom-mendations issued by the World Trade Organization TechnicalBarriers to Trade(TBT)Committee.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD648 T
13、est Method for Deflection Temperature of PlasticsUnder Flexural Load in the Edgewise PositionD792 Test Methods for Density and Specific Gravity(Rela-tive Density)of Plastics by DisplacementD883 Terminology Relating to PlasticsD1430 Classification System for Polychlorotrifluoroethylene(PCTFE)Plastics
14、D1600 Terminology forAbbreviated Terms Relating to Plas-tics1This specification is under the jurisdiction of ASTM Committee D20 onPlastics and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved Nov.1,2018.Published November 2018.Originallyapproved
15、in 2005.Last previous edition approved in 2013 as D7211-13.DOI:10.1520/D7211-13R18.2For 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 the standards Document Summary page on
16、the ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United StatesThis international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for theDevelopment of International Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.1 D2117 Test Methods for Carbon BlackSurface Area byNitrogen
