1、Designation:D244421Standard Practice forDetermination of the Impact Resistance of ThermoplasticPipe and Fittings by Means of a Tup(Falling Weight)1This standard is issued under the fixed designation D2444;the number immediately following the designation indicates the year oforiginal adoption or,in t
2、he 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.Scope*1.1 This practice covers the determination of the impactresistance of thermoplastic pipe and f
3、ittings under specifiedconditions of impact by means of a tup(falling weight).Threeinterchangeable striking noses are used on the tup,differing ingeometrical configuration.Two specimen holders are de-scribed.NOTE1Appendix X1 shows the procedure to determine impactstrength.1.2 The values stated in in
4、ch-pound units are to be regardedas standard.The values given in parentheses are mathematicalconversions to SI units that are provided for information onlyand are not considered standard.1.3 This standard does not purport to address all of thesafety concerns,if any,associated with its use.It is ther
5、esponsibility of the user of this standard to establish appro-priate safety,health,and environmental practices and deter-mine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accor-dance with internationally recognized principles on standard-i
6、zation 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 TestingD160
7、0 Terminology forAbbreviated Terms Relating to Plas-ticsD2122 Test Method for Determining Dimensions of Ther-moplastic Pipe and FittingsF412 Terminology Relating to Plastic Piping SystemsF725 Practice for Drafting Impact Test Requirements InThermoplastic Pipe And Fittings Standards3.Terminology3.1 D
8、efinitionsDefinitions are in accordance with Termi-nology F412,and abbreviations are in accordance with Termi-nology D1600,unless otherwise specified.3.2 Definitions of Terms Specific to This Standard:3.2.1 tupThe striking part of a falling hammer like mecha-nism.4.Significance and Use4.1 The impact
9、 resistance of thermoplastic pipe and fittingsrelates to suitability for service and to quality of processing.Impact resistance may also provide a relative measure of amaterials resistance to breakage during handling and installa-tion and,for non-buried applications,to in-service breakage.See Append
10、ix X5 for guidelines for selecting testing combi-nations.4.2 Results obtained by use of this practice can be used inthree ways:4.2.1 As the basis for establishing impact test requirementsin product standards,4.2.2 To measure the effect of changes in materials orprocessing,and4.2.3 To measure the eff
11、ect of the environment.5.Apparatus5.1 GeneralOne type of impact tester is illustrated in Fig.1.5.2 Tup:5.2.1 The tup nose shall be as shown in Fig.2.When usedwith the 0.50 in.(12.7 mm)radius nose,it is designated as TupA.When used with the 2.00 in.(51 mm)radius nose,it isdesignated as Tup B.When use
12、d with the 0.25 in.(6.3 mm)radius nose,it is designated as Tup C.NOTE2It is suggested that tups be made of scratch-resistant steel toreduce damage to the nose.Badly scarred noses may affect test results.5.2.2 The mass of the tup shall be 6,12,20,or 30 lb(2.7,5.4,9.1,or 13.6 kg).1This practice is und
13、er the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.40 on TestMethods.Current edition approved Feb.1,2021.Published February 2021.Originallyapproved in 1965.Last previous edition approved in 2019 as D2444 19.DOI:10.1520/D2444-21.2Fo
14、r 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.*A Summary of Changes section appears at the end of this standardCopy
15、right 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
16、Standards,Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade(TBT)Committee.15.3 Drop Tube:5.3.1 The drop tube shall be of sufficient length(approxi-mately 12 ft(3.7 m)to provide for a fall of at least 10 ft(3.0m)and shall be mounted so that the lengthwise direction isvertical as measured with a plumb bob or a spirit level at least2 ft(610 mm)in length.5.3.2 Care must be taken to ensure that the tup falls freely;it must not“chatter”down the tube.NOTE3No
