Substitution of Carbon Steels for ASME SA-533 Type E for Lightweight Equipment

Abstract : The use of MnMo(Ni) alloys ASME SA-533 type B or type C in lieu of carbon manganese steels (SA-516 Grade 65 or Grade 70) started about 30 years ago to produce lightweight pressure vessels. But the development of these low alloy steels for the fabrication of equipment for wet H2S service ("sour service") remains limited due to their weldability considered as challenging. This paper aims at introducing newly developed material ASME SA-533 type E class 2, and provides results obtained in base metal and welded joints, especially with respect to NACE standard MR0175 / ISO 15156-2. Finally, a case study on an absorber for amine gas treating units (AGRU) will be described to illustrate the mass savings that can be achieved with SA-533 type E class 2.