This specification covers wrought carbon steel and alloy steel fittings of seamless and welded construction. These fittings are for use in pressure piping and in pressure vessel fabrication for service at moderate and elevated temperatures. The material for fittings shall consist of killed steel, forgings, bars, plates, seamless or fusion-welded tubular products with filler metal added. Forging or shaping operations may be performed by hammering, pressing, piercing, extruding, upsetting, rolling, bending, fusion welding, machining, or by a combination of two or more of these operations. The forming procedure shall be so applied that it will not produce injurious imperfections in the fittings. Fittings, after forming at an elevated temperature, shall be cooled to a temperature below the critical range under suitable conditions to prevent injurious defects caused by too rapid cooling, but in no case more rapidly than the cooling rate in still air. The fittings shall be subjected to tension test, hardness test, and hydrostatic test.
1.1 This specification covers wrought carbon steeland alloy steel fittings of seamless and welded constructioncovered by the latest revision of ASME B16.9, B16.11, MSS-SP-79,MSS-SP-83, MSS-SP-95, and MSS-SP-97. These fittings are for use inpressure piping and in pressure vessel fabrication for service atmoderate and elevated temperatures. Fittings differing from theseASME and MSS standards shall be furnished in accordance withSupplementary Requirement S58 of Specification A960/A960M.
1.2 Optional supplementary requirements are providedfor fittings where a greater degree of examination is desired. Whendesired, one or more of these supplementary requirements may bespecified in the order.
1.3 This specification does not cover cast weldingfittings or fittings machined from castings. Cast steel weldingfittings are governed by Specifications A216/A216M and A217/A217M.
1.4 This specification is expressed in bothinch-pound units and in SI units. However, unless the orderspecifies the applicable “M” specification designation (SI units), thematerial shall be furnished to inch-pound units.
1.5 The values stated in either SI units orinch-pound units are to be regarded separately as standard. Withinthe text, the SI units are shown in brackets. The values stated ineach system may not be exact equivalents; therefore, each systemshall be used independently of the other. Combining values from thetwo systems may result in non-conformance with the standard.