The removal of mandatory Post Weld Heat Treatment (PWHT) for P1 group CMn steels thicker than 0.75 inch in the 2014 edition of ASME B31.3 (and later editions) prompted EEMUA member companies to develop this publication. If PWHT is performed incorrectly, or neglected altogether, residual stresses can combine with load stresses to exceed a material’s design limitations. This can lead to weld failures, higher cracking potential and increased susceptibility to brittle fracture.
EEMUA 235 provides guidance to designers of piping systems on the threshold thickness for PWHT of P1 steels. It also advises on the benefit of PWHT for P1 steels when selected for low temperature applications, such as in the offshore oil and gas sector. EEMUA commissioned fracture mechanics specialists to create a new set of design curves for P1 steels based on ASME B31.3 and API 579 which are included in the publication.
Please note EEMUA Associates receive a 50% discount off the non-member price.