Improving the safety of pressure equipments: some examples of the use of QT steels

Abstract

Normalized steels are widely used in the pressure equipment industry and most of the safety rules have been established based on the properties of these steels. In the past, the use of quenched and tempered steels was limited to the biggest pressure vessels to achieve the mechanical properties at quarter or mid-thickness. The paper describes three examples of use of QT steels manufactured by Industeel and used in PWHT or in as-welded condition: the use of CARELSO 355 HRS (P355QL type) for pressure vessels operating in sour service and resistant to the SOHIC phenomenon; the use of SUPERELSO 500 HR (P500QL type) for pressure vessels operating in sour service (separators, scrubbers...) but when weight saving is of major importance; the use of SUPERELSO 702 for the racks of jack-up platforms and the results of P690QL steel grade in ECOPRESS research.