NATURE OF DEFECT
The 24” line had suffered from external corrosion. This resulted in several through wall defects along the butt weld near the flange. After further inspection, some additional pitting was found up the top of the elbow. The client required 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 Herculyte epoxies and a specialised injectable composite system to seal the leaks with a minimum overwrap of 8 layers of Dragon Q-STD composite at the holed defect area and over the flange, and 6 layers going up the elbow.
REPAIR METHOD
Metalyte Pipeworks high strength, high tensile composite system was used to arrest the leaks and the substrate surface was prepared using an MBX machine to gain a surface profile to SSP.SP11. Dragon resin was applied as a bonding coat prior to application of the Dragon composite. The initial wrap repair area was wrapped in 8 layers of Engineered Dragon Q-STD. Once cured, the flanges were profiled and an overwrap of a further 8 layers was applied going from the brick wall, over the flange and over the initial wrap landing onto the pipe past the initial wrap with the wrap continuing with 6 layers up the elbow. The composite repair was cured until a minimum of 74.5 “Shore D” hardness was achieved.
