1、Designation:D265707(Reapproved 2015)Standard Practice forHeat Fusion Joining of Polyolefin Pipe and Fittings1This standard is issued under the fixed designation D2657;the number immediately following the designation indicates the year oforiginal adoption or,in the case of revision,the year of last r
2、evision.A number in parentheses indicates the year of last reapproval.Asuperscript epsilon()indicates an editorial change since the last revision or reapproval.This standard has been approved for use by agencies of the U.S.Department of Defense.1.Scope1.1 This practice describes general procedures f
3、or makingjoints with polyolefin pipe and fittings(excluding polyethylenepipe and fittings)by means of heat fusion joining techniques ineither a shop or field environment.These procedures aregeneral ones.Specific instructions for heat fusion joining areobtained from product manufacturers.See Practice
4、 F2620 forheat fusion joining of polyethylene pipe and fittings.1.2 The techniques covered are applicable only to joiningpolyolefin pipe and fittings of related polymer chemistry,forexample,polypropylenes to polypropylenes,or polybutylenesto polybutylenes.Material,density,and flow rate shall be take
5、ninto consideration in order to develop uniform melt viscositiesand formation of a good fusion bond when joining the samematerial to itself or to other materials of related polymerchemistry.1.3 Parts that are within the dimensional tolerances given inpresent ASTM specifications are required to produ
6、ce soundjoints between polyolefin pipe and fittings when using thejoining techniques described in this practice.1.4 The values stated in inch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand ar
7、e not considered standard.1.5 The text of this practice references notes,footnotes,andappendixes which provide explanatory material.These notesand footnotes(excluding those in tables and figures)shall notbe considered as requirements of the practice.1.6 This standard does not purport to address all
8、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 determine the applica-bility of regulatory limitations prior to use.See specific safetyprecautions in 3.1.1,5.2,8.2.3.1,Note 8 and Note
9、9,and A1.1.2.Referenced Documents2.1 ASTM Standards:2F1056 Specification for Socket Fusion Tools for Use inSocket Fusion Joining Polyethylene Pipe or Tubing andFittingsF2620 Practice for Heat Fusion Joining of Polyethylene Pipeand Fittings3.Summary of Practice3.1 Heat-fusion joining uses a combinati
10、on of heat and forceresulting in two melted surfaces flowing together to produce ajoint.Fusion bonding occurs when the joint cools below themelt temperature of the material.There is a temperature rangewithin which any particular material is satisfactorily joined.The specific temperature used require
11、s consideration of theproperties of the specific material,and the joining environment.With Techniques II or III(3.3.2 or 3.3.3),there is also anappropriate force to be applied which depends upon thematerial,the fusion equipment being used,and fusion tempera-ture.See Practice F2620 for heat fusion pr
12、ocedure for poly-ethylene pipe and fittings.3.1.1 Electrically powered heat fusion tools and equipmentare usually not explosion proof.When performing heat fusionin a potentially combustible atmosphere such as in an excava-tion where gas is present,all electrically powered tools andequipment that wil
13、l be used in the combustible atmosphereshall be disconnected from the electrical power source andoperated manually to prevent explosion and fire.For theheating tool,this requires bringing the heating tool up to orslightly above temperature in a safe area,then disconnecting itfrom electrical power im
14、mediately before use.This procedureis limited to smaller sizes where heating is accomplishedbefore the heating tool drops below acceptable temperature.3.2 Adequate joint strength for testing is attained when allof the joint material cools to ambient temperature.The jointshall not be disturbed or mov
15、ed until it has cooled.See PracticeF2620 for heat fusion procedure for polyethylene pipe andfittings.1This practice is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.20 on Joining.Current edition approved Dec.1,2015.Publishe
16、d December 2015.Originallyapproved in 1967.Last previous edition approved in 2007 as D2657 07.DOI:10.1520/D2657-07R15.2For 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 onthe ASTM website.Copyright ASTM International,100 Barr Harbor Drive,PO Box C700,West Conshohocken,PA 19428-2959.United States1 NOTE1Polybutylene undergoes a crystall
