ASTM_F_2768_-_09.pdf

Designation:F276809Standard Specification forModified Stub ACME Thread Joint with Elastomeric Seal inPlastic Piping Components1This standard is issued under the fixed designation F2768;the number immediately following the designation indicates the year oforiginal adoption or,in the 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 covers a Modified Stub ACMEThread Joint with an Elastomeric Seal used to seal the jointcomponents in plastic piping components,or(if applicable)tocomponents made of other non-plastic materials used forplastic piping components used in turf irrigation systems.1.2 This specification establishes requirements for dimen-sions and gauging of Modified Stub ACME Thread andElastomeric seal.1.3 Tapered pipe threads are not covered in this specifica-tion.NOTE1The terms“bottom out”and“back off”are used to implycomplete engagement of the threaded connection and un-threading of theconnection and do not imply using a pipe wrench or other tools whichwould damage plastic pipe and fittings.1.4 The values stated in inch-pound units are to be regardedas standard.No other units of measurement are included in thisstandard.1.5 This standard does not purport to address all 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.2.Referenced Documents2.1 ASTM Standards:2D1600 Terminology forAbbreviated Terms Relating to Plas-ticsF412 Terminology Relating to Plastic Piping SystemsF477 Specification for Elastomeric Seals(Gaskets)for Join-ing Plastic PipeF1970 Specification for Special Engineered Fittings,Appur-tenances or Valves for use in Poly(Vinyl Chloride)(PVC)or Chlorinated Poly(Vinyl Chloride)(CPVC)Systems3.Terminology3.1 Terminology is in accordance with Terminology F412and abbreviations are in accordance with Terminology D1600,unless otherwise indicated.4.Significance and Use4.1 Connections made in accordance with these specifica-tions consist of a Modified Stub ACME external and aModified Stub ACME internal thread,in addition to anelastomeric seal.The threaded connections are intended toprovide limited radial movement of the internal and externalthreaded components while maintaining a pressure tight andleak-tight connection.Sealing is affected by the elastomericseal and not between the threaded parts in final assembly.5.Classification5.1 Thread FormThe form of thread profile specified inthis specification shall be known as the Modified Stub ACMEThread Form.The relations as specified herein,for form ofthread and general notations are shown in Table 1 and Table 2.5.2 Thread DesignationsThe type of pipe threads includedin this specification are designated by specifying in sequencethe nominal pipe size,number of threads per inch,and thethread series symbols as follows:112-10 Modified StubACMEwhich indicates a 112Iron Pipe Size,10 threads per inch,righthand,single thread.For left-hand threads add LH to thedesignation,otherwise right-hand threads will be understood.For example:114-10 Modified Stub ACME LH.6.Dimensions and Tolerances6.1 Female Threads:6.2 Thread StartsMachinedFeathered starts are pro-duced by a 45 chamfer on the first thread when the thread iscut with a tap or die.The depth of chamfer shall be from34to114thread deep.Feathered starts are prone to crossing andmutilation and shall not be molded.6.3 Thread StartsMoldedInternal and external moldedthreads shall begin with a taper or blunt start.A pilot shall beprovided from the face of the fitting and at the entering end of1This specification is under the jurisdiction of ASTM Committee F17 on PlasticPiping Systems and is the direct responsibility of Subcommittee F17.10 on Fittings.Current edition approved Dec.1,2009.Published January 2010.DOI:10.1520/F276809.2For 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 the external threads;it shall have a length to the start(flank)ofthe first thread,equal to12to34the width of the thread pitch,1 to 114thread pitch to the centerline.(Thread pitch equals oneturn.)The pilot shall be included in the measurement of thethread length.Taper starts on the first thread are formed by thethread rising from the minimum to maximum diameter whilemaintaining the ACME thread profile.The length of rise shallnot exceed18turn(45).6.4 Blunt starts on the first thread are formed by the threadrising from the minimum to maximum diameter while main-taining theACME thread profile.The length of rise s