ASTM A234 refers to pipe fittings of wrought carbon steel and alloy steel for use in moderate and elevated temperatures. Typical applications include pressure piping and pressure vessel fabrication. The material consists of killed steel, forgings, bars, plates, sheet, and seamless or fusion-welded tubular products with filler metal added.
A234-WP22 Alloy Steel for Moderate and High Temperature Service
1. Scope
1.1 this specification covers wrought carbon steel and alloy steel fittings of seamless and welded construction covered by the latest revision of ASME B16.9 , B16.11 ,MSS-SP-79,MSS-SP—83,MSS-SP-95 and MSS-SP-97 .
These fittings are for use in pressure piping and in pressure vessel fabrication for service at moderate and elevated temperatures. Fittings differing from these ASME and MSS standards shall be furnished in according with Supplementary Requirement S58 of Specification A960/A960M.
1.2 optional supplementary requirements are provided for fitting where a greater degree of examination is desired . When desired , one of more of these supplementary requirements may be specified in the order.
1.3 This specification does not cover cash welding fittings or fittings machined from castings. Cast steel welding fittings are governed by Specification A216/A216M and A217/A217M .
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 SI units or inch-pound units are to be regarded separately as standard . Within the text , the Si units are shown in brackets . the value stated in each system may not be exact equivalents ; therefore ; each system shall be used independently of the order . Combining values from the two systems may result in non-conformance with the standard .
| ASTM A234 Carbon Steel and Alloy Steel Chemical Composition, % | ||||||||||
| Grade | C | Mn | P max | S max | Si | Cr | Mo | Ni | Cu | Others |
| WPB (1,2,3,4,5) | 0.30 max | 0.29- 1.06 | 0.050 | 0.058 | 0.10 min | 0.40 max | 0.15 max | 0.40 max | 0.40 max | V 0.08 max |
| WPC (2,3,4,5) | 0.35 max | 0.29- 1.06 | 0.050 | 0.058 | 0.10 min | 0.40 max | 0.15 max | 0.40 max | 0.40 max | V 0.08 max |
| WP1 | 0.28 max | 0.30- 0.90 | 0.045 | 0.045 | 0.10- 0.50 | 0.44- 0.65 | ||||
| WP12 CL1 | 0.05- 0.20 | 0.30- 0.80 | 0.045 | 0.045 | 0.60 max | 0.80- 1.25 | 0.44- 0.65 | |||
| WP12 CL2 | 0.05- 0.20 | 0.30- 0.80 | 0.045 | 0.045 | 0.60 max | 0.80- 1.25 | 0.44- 0.65 | |||
| WP11 CL1 | 0.05- 0.15 | 0.30- 0.60 | 0.030 | 0.030 | 0.50- 1.00 | 1.00- 1.50 | 0.44- 0.65 | |||
| WP11 CL2 | 0.05- 0.20 | 0.30- 0.80 | 0.040 | 0.040 | 0.50- 1.00 | 1.00- 1.50 | 0.44- 0.65 | |||
| WP11 CL3 | 0.05- 0.20 | 0.30- 0.80 | 0.040 | 0.040 | 0.50- 1.00 | 1.00- 1.50 | 0.44- 0.65 | |||
| WP22 CL1 | 0.05- 0.15 | 0.30- 0.60 | 0.040 | 0.040 | 0.50 max | 1.90- 2.60 | 0.87- 1.13 | |||
| WP22 CL3 | 0.05- 0.15 | 0.30- 0.60 | 0.040 | 0.040 | 0.50 max | 1.90- 2.60 | 0.87- 1.13 | |||
| WP5 CL1 | 0.15 max | 0.30- 0.60 | 0.040 | 0.030 | 0.50 max | 4.0- 6.0 | 0.44- 0.65 | |||
| WP5 CL3 | 0.15 max | 0.30- 0.60 | 0.040 | 0.030 | 0.50 max | 4.0- 6.0 | 0.44- 0.65 | |||
| WP9 CL1 | 0.15 max | 0.30- 0.60 | 0.030 | 0.030 | 1.00 max | 8.0- 10.0 | 0.90- 1.10 | |||
| WP9 CL3 | 0.15 max | 0.30- 0.60 | 0.030 | 0.030 | 1.00 max | 8.0- 10.0 | 0.90- 1.10 | |||
