ASTM A234 is standard specification for wrought carbon steel & alloy steel pipe fittings which covers seamless and welded types.
They are available in latest revision of ASME B16.9, B16.11, MSS-SP-79, MSS-SP-83, MSS-SP-95, and MSS-SP-97. Also widely used in pressure piping and in pressure vessel fabrication for service at moderate and elevated temperatures. The grades are ASTM A234 WPB, WPC, WP5, WP9, WP91, WP11, WP12 and WP22.
2. What's WPB
W = WELDABLE / wrought
P = RELATED TO P NUMBER OF ALLOY MATERIAL
B = REFER TO MINIMUM YIELD OF MATERIAL
3. ASTM A234 WPB Pipe Fittings Process Procedure
Hot-formed A234 WPB and WPC pipe fittings finished at temperature in excess of 1800°F[980°C] shall be subsequently annealed, normalized, or normalized and tempered. The A234 WPB butt-welding pipe fittings include elbow, bend, tee, reducer, end cap, cross, lap joint stub end and nipple.