ASTM A 403 - 2001 Specification for Wrought Austenitic Stainless Steel Piping Fittings

This specification covers wrought stainless steel fittings for pressure piping applications.
Several grades of austenitic stainless steel alloys are included in this specification, Grades are designated with a prefix, WP or CR, based on the applicable ANSI or MSS dimensional and rating standards, respectively.
For each of the WP stainless grades, several classes of fittings are covered, to indicate whether seamless or welded construction was utilized. Class designations are also utilized to indicate the nondestructive test method and extent of nondestructive examination (NDE).