403 / SA 403
Specification for Wrought Austenitic Stainless Steel
1.1 This specification covers wrought
stainless steel fittings for pressure piping applications.
1.2 Several grades of austenitic
stainless steel alloys are included in this specification.
Grades are designated with a WP or CR based on the
applicable ANSI or MSS dimensional and rating standards,
1.3 For each of the WP stainless
grades, several classes of fittings are covered,
to indicate whether seamless or welded construction
was used. Class designations are also used to indicate
the nondestructive test method and extent of nondestructive
examination (NDE). A table gives the general summary
of the fitting classes applicable to all WP grades
of stainless steel covered by this specification.
There are no classes for the CR grades. Specific
requirements are covered under another specification.
1.4 This specification is expressed
in both inch-pound units and in SI units. However,
unless the order specifies the applicable "M"
specification designation (SI units), the material
shall be furnished to inch-pound units.
1.5 The values stated in either
inch-pound units or SI units are to be regarded
separately as the standard. (A combination of values
from the two systems may result in nonconformance
with the specification.)
1.6 This specification does not
apply to cast steel fittings. Austenitic stainless
steel castings are covered in Specifications A 351/A
351M, A 743/A 743M, and A 744/A 744M.