1、Designation:D721113Standard 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 case of revision
2、,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.Scope*1.1 This specification is intended to be a means of callingout finished machined parts ready for commercial use.1
3、.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(containing pigments
4、 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 ammonia,gaseous h
5、ydrogen,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 made of 100%PCT
6、FE 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 partsinclude seals,gaskets,
7、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 removed and repla
8、ced 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 dimensionalrelaxation in the vicini
9、ty 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 are for informat
10、ion 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 establish appropriate s
11、afety and healthpractices and determine the applicability of regulatory limita-tions prior to use.NOTE3There is no known ISO equivalent to this standard.2.Referenced Documents2.1 ASTM Standards:2D618 Practice for Conditioning Plastics for TestingD648 Test Method for Deflection Temperature of Plastic
12、sUnder 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)PlasticsD1600 Terminology forAbbreviated Terms Relating
13、to Plas-ticsD2117 Test Methods for Carbon BlackSurface Area byNitrogen Adsorption(Withdrawn 1999)3D4591 Test Method for Determining Temperatures andHeats of Transitions of Fluoropolymers by DifferentialScanning Calorimetry1This specification is under the jurisdiction of ASTM Committee D20 onPlastics
14、 and is the direct responsibility of Subcommittee D20.15 on ThermoplasticMaterials.Current edition approved May 1,2013.Published May 2013.Originallyapproved in 2005.Last previous edition approved in 2006 as D7211-06.DOI:10.1520/D7211-13.2For referenced ASTM standards,visit the ASTM website,www.astm.
15、org,orcontact ASTM Customer Service at serviceastm.org.For Annual Book of ASTMStandards volume information,refer to the standards Document Summary page onthe ASTM website.3The last approved version of this historical standard is referenced onwww.astm.org.*A Summary of Changes section appears at the
16、end of this standardCopyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 D7194 Specification for Aerospace Parts Machined fromPolychlorotrifluoroethylene(PCTFE)3.Terminology3.1 Definitions:3.1.1 Terms are defined in accordance with TerminologiesD883 and D1600 unless listed below.3.1.2 oxygen media,nliquid oxygen and gaseous oxygen.3.1.3 air media,nliquid air and pressurized air(includingbreathing air).3.1.4 inert media,nfor example,gaseous
