ASME B16.5a:1998 pdf download PIPE FLANGES AND FLANGED FITTINGS
1 SCOPE
1.1 General
This Standard covers pressure-temperature ratingsmaterials, dimensions. tolerances, marking. testing. andmethods of designating openings for pipe flanges andflanged fittings in sizes NPS % through NPS 24 andin rating Classes 150,300,400，600,900,1500,and2500. Flanges and flanged fittings may be cast, forged,or (for blind fanges and certain reducing flanges only)plate materials as listed in Table 1A.Requirements and recommendations regarding boltingand gaskets are also included.
1.2 References
1.21 Referenced Standards. Standards and specifications adopted by reference in this Standard areshown in Annex H which is part of this Standard. Itis not considered practical to identify the specific editionof each standard and specification in the individualreferences. Instead, the specific edition reference isidentified in Annex H. A fange or flanged fittingmanufactured in accordance with earlier editions of thereferenced standards and in all other respects conformingto this Standard will be considered to be in conformancewith this Standard.
1.2.2 Codes and Regulations. A fange or flangedfitting used under the jurisdiction of the ASME Boilerand Pressure Vessel Code, the ASME Code for PressurePiping, or a governmental regulation is subject to anylimitation of that code or regulation, This includes anymaximum temperature limitation or rule governing theuse of a material at low temperature, or provisionsfor operation at a pressure exceeding the pressure-temperature ratings in this Standard.
1.3 Applicable Ratings
The pressure-temperature ratings in this Standardare applicable upon its publication to all fanges andflanged fittings within its scope which otherwise meetits requirements. For unused flanges or flanged fittingsmaintained in inventory, the manufacturer of the flangeor flanged fittings may certify conformance to thisEdition provided he can demonstrate that all require-ments of this Edition have been met.Where such components were installed in accordance with the pressure-temperature ratings of an earlier edition of thisStandard, those ratings are applicable except as maybe governed by the applicable code or regulation (seepara1.2.2).
1.4 User Accountability
This Standard cites duties and responsibilities thatare to be assumed by the user in the areas of application,installation, hydrostatic testing, operation, and materialselection.
1.5 Quality Systems
Nonmandatory requirements relating to the productmanufacturer’s Quality System Program are describedin Anncx G.
2 PRESSURE-TEMPERATURE RATINGS
2.1 Ratings Basis
Ratings are maximum allowable working gage pressures at the temperatures shown in Table 2 for theapplicable material and rating. For intermediate temperatures, lincar interpolation is permmitted. See Annex D formethods of establishing pressure-temperature ratings
2.2 Ratings of Flanged Joints
A flanged joint is composed of three separate andindependent，although interrelated components: theflanges, the gasket, and the bolting, which are assembledby yet another influence, the assembler, Proper controlsmust be exercised in the selection and application forall these elements to attain a joint which has acceptableleak tightness. Special techniques, such as controlledbolt tightening, may be necessary to achieve a tightjoint in service.
Ratings in this Standard apply to flanged joints whichconform to the limitations on bolting in para. 5.3 andon gaskets in para. 5.4, and which are made up inaccordance with good practice for alignment and assem-bly. See also para. 2.4. Use of the ratings for flangedjoints not conforming to these limitations is the responsi-bility of the user. Requirements for alignment andassembly of joints are not given in this Standard.
ASME B16.5a:1998 pdf download
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