A number of high pressure gas transportation lines have been built in the past using spiral welded pipes, however no specific recommendation exists about the toughness of the spiral pipes required for the arrest of a running ductile fracture, although the current EPRG recommendations on fracture arrest toughness do include spiral welded pipes. The paper presents the work, carried out on behalf of EPRG, aimed at analysing the ductile fracture behaviour of spiral welded pipes in comparison with longitudinal ones, tested in similar conditions. Available full scale burst tests carried out on spiral welded pipes have been collected and the ability of the fracture arrest criterion adopted by EPRG verified. Given that a number of tests on spiral pipes has been carried out using rich gas as a pressurising medium, an analysis of its influence on ductile fracture propagation using the conventional Battelle approach has been performed. All results found show that the ability of spiral welded pipes to arrest ductile running fracture is at least as good as longitudinal welded ones.
展开▼
