NATURE OF DEFECT
The 24” line had suffered from external corrosion at different points on the pipeline which was repaired with composites. One non wrapped area has gone through wall and was clamped over. Over time this clamp started to show signs of leakage, as the clamp loosened up.
The client requires a composite wrap over the original wraps and original clamp to bring the line back up to its full design specification.
SOLUTION
Metalyte Pipeworks produced a repair method using Herculyte epoxies and sealants to seal the weep and to smooth the defects and the clamp was profiled with a minimum overwrap of 60 layers of Dragon-QUAD UHT composite system.
REPAIR METHOD
Natural fibre absorbent was utilised were any signs of oil weeping appeared from the clamp. The surface was then prepared by on site shot blasters to Sa 2.5. In tight areas hand tools were used where necessary to gain the required surface roughness of SSPC.SP2.
The clamp was profiled and a minimum of 500 microns of Dragon resin was applied as a bonding coat to the entire repair area prior to application of the Dragon composite. The repair area was wrapped in 60 layers of Engineered Dragon QUAD-UHT composite and cured until a minumim of 74.5 “Shore D” hardness was achieved.
