EN 10253-2 Type B buttweld fittings in all carbon steel pressure grades — P235GH, P265GH, P295GH, P275NH. The most widely used material class for European pressure piping systems.
Lowest carbon steel pressure grade. 235 MPa minimum yield strength. The standard grade for utility steam, hot water, and moderate-pressure gas piping. ASTM A234 WPB approximate equivalent.
265 MPa yield strength. Standard boiler and pressure vessel grade. Used for steam generation systems, heat exchangers, and gas processing. Broader temperature range than P235GH.
295 MPa yield strength — highest of the carbon steel GH pressure grades. Specified when wall thickness reduction is needed, or wherever P265GH is marginal. One step below CrMo alloy grades.
NH grade: normalised, high weldability, ambient-temperature structural and distribution piping. Not a pressure boiler grade. For water, gas distribution, structural fabrication, and marine piping.
EN 10028-3 NL-grades for sub-zero service — Charpy impact tested at −50°C. Required by PED for MDMT below −10°C. European equivalents of ASTM A420 WPL6 and WPL3.
275 MPa yield. Charpy 40 J at −50°C. European equivalent of ASTM WPL6. LPG storage, refrigeration piping, cold gas service, offshore cold-climate topsides.
355 MPa yield. Charpy 40 J at −50°C. Higher yield than P275NL1 allows thinner walls at same pressure. LNG satellite stations, cold gas high-pressure headers, Arctic offshore.
| Grade | EN Number | Yield Strength | C max | Max Temp | Application |
|---|---|---|---|---|---|
| P235GH | 1.0345 | 235 MPa | 0.16% | 300°C | Utility steam, hot water, gas |
| P265GH | 1.0425 | 265 MPa | 0.20% | 400°C | Boilers, pressure vessels, steam |
| P295GH | 1.0566 | 295 MPa | 0.22% | 400°C | High-pressure boiler, steam drum |
| P275NH | 1.0473 | 275 MPa | 0.18% | Ambient | Structural, water/gas distribution |
Carbon steel GH grades are limited to approximately 400°C for sustained pressure service. Above this temperature, creep deformation becomes significant and carbon steel allowable stresses drop sharply. For service above 400°C, move to the CrMo alloy steel grades — P11 (1.7335) at 1.25Cr-0.5Mo is the first step, followed by P22 (1.7380) and higher grades for more demanding service. Also consider CrMo when hydrogen partial pressure is significant — carbon steel is susceptible to Nelson curve HTHA above ~230°C at H₂ partial pressures seen in hydroprocessing.
EN 10253-2 Type B. EN 10204 3.1 standard. PED 2014/68/EU. Sizes DN15–DN600. Contact us with fitting schedule, grade, and delivery location.
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