Nature of defect
The 8” line had suffered from internal corrosion/erosion. This resulted in a through wall leaking defect close to the valve flange assembly at the 4 o’clock position. The client requires a composite repair to seal the leak locations and to bring the line back up to its full design specification.
Solution
Metalyte Pipeworks produced a repair method using their composite injectable system to seal the leaks with a minimum overwrap of 4 layers of Dragon-Q-STD composite system.
Repair method
Metalyte Pipeworks sealed the leaks using their high strength injectable composite collar. The carbon steel substrate was then prepared (excluding the identified defect area) using an MBX machine to gain a surface profile to SSP.SP11. Surface defects within the immediate repair area were repaired and the geometry of the flange/valve were profiled effectively to allow for a smooth composite transition. 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 4 layers of Engineered Dragon-Q-STD composite and allowed to cure until a minimum of 74.5 “Shore D” hardness was achieved.
