Pipesafe, engineering critical assessment software for pipe line girth welds

Abstract

The Australian Standard for Pipeline Construction, AS2885 (1995), considers pipeline girth weld defect acceptance using Tier 1 (workmanship standards), Tier 2 (fitness for purpose) and by Engineering Critical Assessment (ECA) as Tier 3. AS2885 makes provision for ECA in clause 22.4 by stating "if approved the acceptable criteria may be determined by using an approved ECA procedure or other approved method". The ‘fitness for purpose‘ approach adopted in AS2885 is related to that originating from the European Pipeline Research Group (EPRG). However, ECA is currently an unwieldy tool and unattractive to those who have only an occasional need to carry out assessment using fracture mechanics. This paper discusses the software PIPESAFE that has been developed to apply ECA defect acceptance methodology to girth welds in pipelines being built in Australia.

PIPESAFE is a PC based software package which aims to enable pipeline engineers to assess the significance of flaws and is based on principles embodied in PD6493, 1991 ‘Guidance on Methods for Assessing the Acceptibility of Flaws in Fusion Welded Structures”. The software is currently being trialed in industry and will be commercially available in the near future.