ASME B16.34:04 pdf download.Valves- Flanged,Threaded, and Welding End.
1.1 General
This Standard applies to new construction and covers pressure-temperature ratings, dimensions, tolerances, materials, nondestructive examination requirements, testing, and marking for cast, forged, and fabricated flanged, threaded, and welding end and wafer or flangeless valves of steel, nickel-base alloys, and other alloys shown in Table 1. Wafer or flangeless valves, bolted or through-bolt types, that are installed between flanges or against a flange are treated as flanged-end valves. Alternative rules for NI’S 21/2 and smaller valves are given in Mandatory Appendix V.
1.2 Applicability
1.2.1 Standards and Specifications. Standards and specifications adopted by reference in this Standard and the names and addresses of the sponsoring organizations are shown in Mandatory Appendix VIII. It is not considered practical to refer to a specific edition of each of the standards and specifications in the individual clause references. Instead, the specific edition references are included in Mandatory Appendix VIII. A product made in conformance with a prior edition of reference standards and in all other respects conforming to this Standard shall be considered to be in conformance even though the edition reference may have been changed in a subsequent revision of this Standard.
1.2.2 Time of Purchase, Manufacture, or Installation. The pressure-temperature ratings included in this Standard are applicable, upon publication, to all valves covered within its scope that meet its requirements. For unused valves, valves which have been maintained in inventory, the manufacturer may certify conformance to this edition provided that it can be demonstrated that all requirements of this edition have been met. However, where such components were installed under the pressure-temperature ratings of an earlier edition of ASME B16.34, those ratings shall apply except as may be governed by an applicable Code or regulation.
1.2.3 User Accountability. This Standard cites duties and responsibilities that are to be assumed by the valve user in the areas of, for example, application, installation, system hydrostatic testing, operation, and material selection.
1.6 References
Codes, standards, and specifications, containing provisions to the extent referenced herein, constitute requirements of this Standard. These reference documents are listed in Mandatory Appendix VIII.
2 PRESSURE-TEMPERATURE RATINGS
2.1 General
Pressure-temperature ratings are designated by class numbers. Each class number is further identified as Standard, Special, or Limited Class.
2.1.1 Rating Designations. Rating designations are tabulated for Standard and Special Class 150, 300, 400, 600, 900, 1500, 2500, and 4500 in Table 2 in metric units and in Mandatory Appendix VII in customary units. Ratings for Limited Class are determined by the method in Mandatory Appendix V.
(a) Flanged-end valves shall be rated only as Standard Class.
(b) Class 4500 applies only to welding-end valves.
(c) A class designation greater than Class 2500 or a rating temperature greater than 538°C (1000°F) applied to threaded-end valves is beyond the scope of this Standard.ASME B16.34 pdf download.