Intelligent pig runs on a BP-operated 175 km, 91 mm pipe line on Shetland revealed an area of external metal loss of up to 28 % of the 19 mm nominal wall thickness caused by active corrosion. A C-Scan survey indicated that the electrical insulation properties of the coal tar enamel wrap had broken down at the location of the defect. After a fitness-for-purpose assessment indicating no risk for the pipe lines integrity a number of repair methods were considered, including welded repair, split sleeve repair, and a composite wrap system. Due to its light weight, comparatively small clearance requirements and resonable costs the composite wrap system turned out to be particularly suited. The Clock Spring composite wrap system consists of a high compressive strength filler compound, an E-glass/polyester composite wrap material, and a two-part adhesive. With this system the repair could be completed in a few hours, without restriction to throughput and pipe line pressure.
BP uses Clock Spring system to repair crude oil pipe line
Pipe Line and Gas Industry ; 84 , 3 ; 75-79
2001
5 Seiten, 5 Bilder, 2 Tabellen
Aufsatz (Zeitschrift)
Englisch