SUPERSEDED (see Active link, below)
Active (view current version of standard)
1.1 This specification covers heat-treated carbon-manganese-silicon steel plates intended for use in welded pressure vessels at moderate and lower temperature service.
2. Material under this specification is available in four strength levels, 75 ksi [515 MPa], 85 ksi [585 MPa], 80 ksi [550 MPa], and 90 ksi [620 MPa] minimum ultimate tensile strengths.
1.3 The maximum thickness of plates is limited only by the capacity of the chemical composition and heat treatment to meet the specified mechanical property requirements; however, current practice normally limits the maximum thickness of plates furnished under this specification to 6 in. [ 150 mm] for Grade A, 4 in. [100 mm] for Grade B, and 6 in. [150 mm] for Grade C. For Grades D and E, the maximum permitted nominal thickness is 1.5 in. [40 mm].
1.4 Grade A is the material that, prior to 1984, was covered by Specification A 738 without a grade designation.
1.5 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.
2. Referenced Documents (purchase separately) The documents listed below are referenced within the subject standard but are not provided as part of the standard.
A20/A20M Specification for General Requirements for Steel Plates for Pressure Vessels
ICS Number Code 77.140.30 (Steels for pressure purposes)
UNSPSC Code 30102204(Steel plate)