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ASME B16.34-2017 pdf download

ASME B16.34-2017 pdf download.Valves — Flanged, Threaded, and Welding End.
1 SCOPE 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,andweldingendandwaferorflangeless valves ofsteel, 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 NPS 2 1 ∕ 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 ofthe sponsoring organiza- tions are shown in Mandatory Appendix VIII. It is not considered practical to refer to a specific edition of each ofthe standards and specifications in the individual clause references. Instead, the specific edition references are included in MandatoryAppendix VIII. Aproductmade inconformancewithaprioreditionofreferencestandards and in all other respects conformingto this Standard shall be considered to be in conformance even though the edition reference mayhave been changed in a subsequent revision of this Standard. 1.2.2 Time ofPurchase, Manufacture, orInstallation. 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 that have been maintained in inventory, the manufacturer may certify conformance tothiseditionprovidedthatitcanbedemonstratedthatall requirements of this edition have been met. However, where such components were installed under the pres- sure–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. 1.2.4 Quality Systems. Requirements relating to a valve manufacturer’s Quality System Program are described in Nonmandatory Appendix C. 1.2.5 Relevant Units. This Standard states values in both SI (Metric) and U.S. Customary units. These systemsofunitsaretoberegardedseparatelyasstandard. Within the text, the U.S. Customary units are shown in parentheses or in separate tables that appear in Mandatory Appendix VII. The values stated in each system are not exact equivalents; therefore, it is required that each system of units be used independently of the other. Combiningvalues from the two systems constitutes nonconformance with the Standard. 1.3 Selection of Valve Types and Material Service Conditions Criteria for selection of valve types and materials suitable for particular fluid service are not within the scope of this Standard. 1.4 Convention For determining conformance with this Standard, the convention for fixing significant digits where limits (maximum and minimum values) are specified shall be as defined in ASTM E29. This requires that an observed orcalculatedvalueberoundedofftothenearestunitinthe lastright-hand digitused forexpressingthe limit. Decimal values and tolerances do notimply a particular method of measurement. 1.5 Denotation 1.5.1 Pressure Rating Designation. Class followed bya dimensionless number is the designation for pressure– temperature ratings. Standardized designations are as follows: Class 150 300 600 900 1500 2500 4500 Class 400, an infrequently used flanged-end valve des- ignation, is regarded as an intermediate class designation.
1.6 ð17Þ Cryogenic Service Valves in cryogenic service shall meet the additional requirements specified in MSS SP-134. 1.7 References Codes, standards, and specifications, containing provi- sions to the extent referenced herein, constitute require- ments 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 ð17Þ Rating Designations. Pressure–temperature ratings are tabulated for Standard and Special Class Pressure Rating Designation numbers 150, 300, 600, 900, 1500, 2500, and 4500 in Table 2-1.1 through Table 2-3.19 in metric units and in Mandatory Appendix VII in U.S. Customary units. Ratings for Limited Class are determined by the method in Mandatory Appendix V. 1 (a) Flanged-end valves shall be rated only as Standard Class. Flanged-end valves larger than NPS 60 are beyond the scope of this Standard. (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 (1,000°F) applied to threaded-end valves is beyond the scope of this Standard. (d) Threaded and socket welding-end valves larger than NPS 2 1 ∕ 2 are beyond the scope of this Standard. (e) Except as provided in para. 2.5, the tabulated ratings are the maximum allowable working pressures, expressed as gage pressure, at the temperatures shown. (f) Ratings intermediate to tabulated values are deter- mined by linear interpolation between temperatures within a class number or between class numbers, except that for flanged-end valves interpolation between tabulated classes is not permitted. A further exception is that Class 400 valves having ASME B16.5 or ASME B16.47 flanged ends shall use the intermediate rating method of para. 2.1.5. (g) In all cases, valves shall be constructed so that the body, bonnet or cover, body bolting, and bonnet or cover bolting meet the 38°C (100°F) pressure rating require- ments for the designated pressure class or pressure– temperature rating. However, pressure–temperature ratingsforthevalvemaybeotherwiselimitedbyconstruc- tion details or material design considerations, in which case the requirements of paras. 4.3.3 and 7.2.6 shall be met. 2.1.2 Standard Class Valves. Valves conformingto the requirements of this Standard, except for those meeting the additional requirements ofsection 8 for Special Class valves or of Mandatory Appendix V for Limited Class valves, shall be designated Standard Class valves. Ratings shall not exceed the values that are listed in Table 2-1.1 through Table 2-3.19 with an identifying label “A — Standard Class.” 2.1.3 Special Class Valves. Threaded- or welding-end valves that conform to all the requirements ofpara. 2.1.2, andinadditionhave successfullypassedthe examinations required by section 8, may be designated Special Class valves. Pressure–temperature ratings shall not exceed the values that are listed in Table 2-1.1 through Table 2-3.19 with an identifying label “B — Special Class.” Special Class ratings shall not be used for flanged-end valves. 2.1.4 Limited Class Valves. Welding- or threaded-end valves NPS 2 1 ∕ 2 and smaller that conform to the require- ments of Mandatory Appendix V may be designated Limited Class valves. Pressure–temperature ratings shall not exceed the values calculated in accordance with Mandatory Appendix V. Limited Class ratings shall not be used for flanged-end valves.

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