EN 10253-2 Type B alloy steel buttweld pipe fittings for high-temperature steam service. P11, P22, P91 and P92 CrMo grades for HP/IP boiler piping, superheater/reheater headers, main steam lines, turbine bypass, and hot reheat systems. All fittings supplied with PWHT documentation and EN 10204 3.1 mill certificates.
| Steam Temp | Grade | W.Nr. | PWHT Range | Typical Application |
|---|---|---|---|---|
| Up to 530°C | P11 (1.25Cr-0.5Mo) | 1.7335 | 700–750°C | Subcritical boiler main steam, IP turbine extraction |
| 530–560°C | P22 (2.25Cr-1Mo) | 1.7380 | 700–760°C | Conventional SC main steam, HP boiler section |
| 560–610°C | P91 (9Cr-1Mo-V-Nb) | 1.4903 | 745–775°C | Supercritical main steam, HP hot reheat |
| 610–650°C | P92 (9Cr-1Mo-W) | 1.4901 | 745–775°C | Ultra-supercritical (USC+) main steam and reheat |
All CrMo alloy steel grades (P11 through P92) require post-weld heat treatment (PWHT). Without PWHT, as-welded hardness exceeds code limits and the joint is susceptible to hydrogen-assisted cracking. Arshya supplies CrMo fittings with PWHT performed and documented on the EN 10204 3.1 certificate. Field welds must also be PWHT — responsibility of the erection contractor.
Subcritical boiler main steam and hot water piping below 530°C. Entry-level CrMo for HP steam service. Filler ER80S-B2.
Full grade page →Conventional supercritical main steam to 560°C. Better creep than P11. Filler ER90S-B3.
Full grade page →Supercritical main steam 560–610°C. Filler ER90S-B9 only. Hardness 200–250 HBW post-PWHT. Mn+Ni ≤1.50% in filler.
Full grade page →Ultra-supercritical (USC+) main steam to 650°C. P92-specific W-bearing filler required — not interchangeable with P91 filler.
Full grade page →EN 10204 3.1 mill certificate. Chemical & mechanical test reports. PWHT records and charts. Hardness test report. EN 10253-2 dimensional compliance. PED 2014/68/EU Declaration of Conformity available.
