There are, however, two major drawbacks to this approach. One is the huge cost arising from committing to a large safety factor due to the lack of measured strength data. The other is that the ultimate collapse strength of a group of manufactured pipeline joints varies considerably from joint to joint, even though they are notionally identical. Numerous features of the manufacturing process and materials affect the collapse depth; if the entire design methodology is reliant on destructive tests of just a small sample of pipes, these could, it should be noted, include a rogue pipe with a collapse strength even lower than that permitted by the safety factor.

Ring Testing, a patented method developed by Verderg Pipeline Technology, provides a direct, reliable, non-destructive measurement of a deepwater pipeline joint’s ultimate collapse depth by testing the collapse strength of a short ring cut from the ends of a significant number of sample pipes, leaving them still within tolerance for project deployment.

Read the full article at Offshore Mag.