ASME B16.34:2013 pdf free download – Valves -Flanged,Threaded, and Welding End
1.1 General
This Standard applies to new construction and coverspressure-temperature ratings,dimensions,tolerances,materials, nondestructive examination requirements,testing. and marking for cast,forged, and fabricatedflanged, threaded, and welding end and wafer orflangeless valves of steel, nickel-base alloys, and otheralloys shown in Table 1. Wafer or flangeless valves,bolted or through-bolt types,that are installed betweenflanges or against a flange are treated as flanged-endvalves.Alternative rules for NPS 21/ and smaller valvesare given in Mandatory Appendix V.
1.2 Applicability
1.2.1 Standards and Specifications. Standards andspecifications adopted by reference in this Standard andthe names and addresses of the sponsoring organiza-tions are shown in Mandatory Appendix VmI. It is notconsidered practical to refer to a specific edition of eachof the standards and specifications in the individualclause references.Instead, the specific edition referencesare included in Mandatory Appendix VIII.A productmade in conformance with a prior edition of referencestandards and in all other respects conforming to thisStandard shall be considered to be in conformance eventhough the edition reference may have been changed ina subsequent revision of this Standard.
1.2.2 Time ofPurchase，Manufacture，orlnstallation. The pressure-temperature ratingsincluded in this Standard are applicable, upon publica-tion, to all valves covered within its scope that meet itsrequirements. For unused valves, valves that have beenmaintained in inventory, the manufacturer may certifyconformance to this edition provided that it can be dem-onstrated that all requirements of this edition have beenmet. However, where such components were installedunder the pressure-temperature ratings of an earlieredition of ASME B16.34, those ratings shall apply exceptas may be governed by an applicable Code or regulation.1.2.3 User Accountability.This Standard cites dutiesand responsibilities that are to be assumed by the valveuser in the areas of, for example, application, installa-tion, system hydrostatic testing, operation, and materialselection.
1.2.4 Quality Systems.Requirements relating to avalve manufacturer’s Quality System Program aredescribed in Nonmandatory Appendix C.
1.2.5 Relevant Units.This Standard states valuesin both SI (Metric) and U.s. Customary units. Thesesystems of units are to be regarded separately as stan-dard. Within the text, the U.s.Customary units areshown in parentheses or in separate tables that appearin Mandatory Appendix VII.The values stated in eachsystem are not exact equivalents; therefore, it is requiredthat each system of units be used independently of theother. Combining values from the two systems consti-tutes nonconformance with the Standard.
1.3 Selection of Valve Types and Material Service Conditions
Criteria for selection of valve types and materials suit-able for particular fluid service are not within the scopeof this Standard.
1.4 Convention
For determining conformance with this Standard, theconvention for fixing significant digits where limits(maximum and minimum values) are specified shall beas defined in ASTM E29.This requires that an observedor calculated value be rounded off to the nearest unitin the last right-hand digit used for expressing the limit.Decimal values and tolerances do not imply a particularmethod of measurement.
2.1.2 Standard Class Valves.Valves conforming tothe requirements of this Standard, except for those meet-ing the additional requirements of section 8 for SpecialClass valves or of Mandatory Appendix V for LimitedClass valves, shall be designated Standard Class valves.Ratings shall not exceed the values that are listed inTable 2 with an identifying label “A -Standard Class.”