ASME B16.34:2004 pdf free download – Valves – Flanged,Threaded, and Welding End
1.1 General
This Standard applies to nevw construction and cowerspressune-temperature ratings. dimensions,tolerances,imaterialls, nondestructive examination requirements,trsting,end marking for cast.forged, and fabricatedfllangedi, threadeci, and welding end and wwafer orflangelesics valves of steel, nickell-base alloys. and otherlluys shown in Table i. Wafee or flangeless valves,bolted or through-lbolt ty pes,that are installed betweenflanges or against a flange are treated as flanged-endvalves. Alternative rules for NPS 25and smaller valvesare given in Mndatory Appendix v.
1.2 Applicability
1.2.1 Standards and Specifications.Standarols andspecifications adopted by reference in this Standard andthe names and addreeses of the sponsoring organiza-tions are shown in Mandatory Appendix VII ft is notconsidcrei proctical to refer toü specifuc ediition of eachcof the standdards and specifications in the individdalclause refenences. Insteaci, the specifie edition referencesare included in Mandatory Appenclix VII.A procluctmade in conformance with a phior editicon of referencestandamds and in all other repects conforrming to thisSt.andard shall be considlered to be in cocforance eventhough the edition reference may have been changed ina subsequent revision of this Standamd.
1.2.2 Time of Purchase,Manufacture, or lnstallation.The pressure-temperatuire ratings included in this Stan-dard are applicable, upon publicatiom, ta all valves cov-ered within its scope that meet its requiremenits. Fortanuised valves. valves which have been maintained ininseantory,the manulacturer may oertify conformance tothis edition provided that it can be demonstrated thatall requtirements of this edition have been met. However.where such components were installed under the pres-sure-temperature ratings of an earlier edition of ASMEB16.34, those ratings shall apply except as may be gov-ermed by an applicable Code oe regulation.
1.2.3 user Accountability. This Sandard cites dutiesand responsibilities that are to be assumed by the velveuser in the areas of, for exanmple.application, installa-tioL, system hydrostatic testing. opcration, and matcrialselection.
2.1.2 Standard class Valves. valsves oonforming tothe requirements of this Standand,except foe those meet-ing the additional requircments of Section 8 for SpocialClass salwes or of Mandatory Appendix v for LimitedClass valves, shall be designated Standard Class wallves.Ratings shall not excoed thc walucs that are listed inTable 2 with am icentifying suffix“A“
2.1.3 Special Class Valves.Threaded-or welding-endland in addition have successfully passed the examina-vallves that conform to all the nequirements of pera. 2.1.2.tions required by Section S, may be designatcd SpocinlClass valves.Pressure-tenpereture ratings shall notexcee thve vales that are listed in Table 2 with eniddentifying table number suffix“B.~ 5Special Class rat-inags shall mnvot be used for flanged-end valves.
2.1.4 Limited Class Valves.Welding- or thrcaded-endvallves in sizes NP5 2 and smaller that conforin tothe requirements of Mandatory Appendix v may bedesignated Limitod Class walvecs. Pressuno-teamporaturoratings shall not exooordd the valuczs caleulated in asocor-dance with Mardatory Appendix V. Limited Class rat-ings shall not be used for flamnged-end valves.
2.1.5 Intermediate Rated Valves. A Standard Classor Specinl Class wellding- or threaded-cndi walve or aStamdard Class 400 flanged-end valve may be assignedan intermediate pressure-temperature wating or Class inacecardance with para.6.1.4, prcwided all other applica-ble requirensents eof this Stanclardd are met.Cornr-spond-ingly,an interrnediate pressure rating or Class forL imited Class valves having welding ends ce threadedends may be assigned pressure-termperature ratings asdetermined by the method described in Mandatoryppendix v inconjunction with the interpolation proce-dire described in para.6.1.4,
2.1.6 Valves fabricated by Welding. Avalve madewholly or partly from segments of castings. forgins.bars.plates，or tubular product welded bogetherwillmerit the applicable pressure-temperalure rating only ifa) it conforns tall applicablle require-ncnts of thisStandard lvcld fabrication and heat treatment of weolds arein aecordaawoe with tlieASME Boiler anwd Pressuree Vesse-lCode