EN 10253-2 Type B buttweld pipe fittings in 1.0566 — 1.0566 carbon steel. The highest minimum yield strength (295 MPa) of the European pressure vessel carbon steel series. Suitable for pressure service to 400°C. Specified for thick-wall pressure vessel components where the higher allowable stress of 1.0566 reduces wall thickness requirements compared to P235GH or P265GH. Next step up from 1.0566 is low-alloy steel (P11/1.7335) for temperatures exceeding 400°C.
1.0566 has 30 MPa higher minimum yield than P265GH. In practice this allows a wall thickness reduction of approximately 10% for the same pressure class. For most standard fittings, P265GH is sufficient and more readily stocked. Specify 1.0566 when: (1) the design calculation requires allowables only 1.0566 meets, (2) the vessel or piping specification explicitly calls for 1.0566, or (3) weight reduction in thick-wall nozzles or large-diameter fittings is required.
| W.Nr. | 1.0566 |
| EN Name | 1.0566 |
| ASTM Nearest | A234 WPB / WPC |
| Standard | EN 10253-2 Type B |
Filler: ER70S-6 or E7018. Preheat 100°C for t >20mm. PWHT 580–620°C when specified by design code.
