This specification covers the standard for wrought austenitic stainless steel fittings for pressure piping applications. The material for fittings shall consist of forgings, bars, plates, or seamless or welded tubular products. Forging or shaping operations shall be performed by hammering, pressing, piercing, extruding, upsetting, rolling, bending, fusion welding, machining, or by a combination of two or more of these operations. All fittings shall undergo heat-treatment. Chemical and product analyses shall be performed and shall conform to the required chemical composition in carbon, manganese, phosphorus, sulfur, silicon, chromium, molybdenum, and titanium. Tension test shall be done on the fitting material to determine the tensile properties such as yield strength and tensile strength. Fittings supplied under this specification shall be examined visually for surface discontinuities, surface checks, and mechanical marks.
1.1 This specification covers wrought stainlesssteel fittings for pressure piping applications.
1.2 Several grades of austenitic stainless steelalloys are included in this specification Grades are designatedwith a prefix, WP or CR, based on the applicable ASME or MSSdimensional and rating standards, respectively.
1.3 For each of the WP stainless grades, severalclasses of fittings are covered, to indicate whether seamless orwelded construction was utilized. Class designations are alsoutilized to indicate the nondestructive test method and extent ofnondestructive examination (NDE). Table 1 is a general summary ofthe fitting classes applicable to all WP grades of stainless steelcovered by this specification. There are no classes for the CRgrades. Specific requirements are covered elsewhere.
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.
1.6 This specification does not apply to cast steelfittings. Austenitic stainless steel castings are covered inSpecifications A351/A351M, A743/A743M, and A744/A744M.
TABLE 1 Fitting Classes for WP Grades
|W||Welded||Radiography or Ultrasonic|