Launchpad, November - December 2006
For a full list of proposed, active and closed projects see here
Qualification of dissimilar joints for subsea service
A handful of subsea failures have occurred in dissimilar joints, which are common in subsea systems, typically where clad X65, clad X70, or CRA pipe is joined to forged low alloy steel fittings.
While small in number, these failures have been costly and caused concern over the potential subsea release of produced hydrocarbon fluids. TWI has established a ranking method for the comparison of different dissimilar joint designs in its recently completed GSP 14403 Materials selection for dissimilar joints in subsea hubs. In this work the significance of cathodic protection and hydrogen disbonding at the dissimilar interface was demonstrated.
Further data is required to qualify the performance of currently implemented dissimilar joint designs and that of alternative designs and material combinations, including those detailed in EEMUA 194, for new installations.
In the short term, industry requires data to enable safe operation of existing assets and those which are about to be installed. In order to address this need TWI will be launching a rapid turnaround GSP: TWI proposal PR11207: Phase I: Qualification of dissimilar joints for subsea service. This GSP will be completed within six months, with key deliverables after three months. A further phase II will be proposed to address longer term requirements.
For information, please contact Stuart Bond regarding proposal PR11207, or David Hamper if you would be interested in purchasing the results of TWI GSP 14403.
