NATURE OF DEFECT
The 12” line had suffered from external corrosion. This resulted in a wall thickness reduction over a 380mm length. The client requires a composite repair to reinstate the mechanical integrity, protect from further environmental corrosion and bring the line back up to its full design specification.
SOLUTION
Metalyte Pipeworks produced a repair method using Herculyte epoxies to build up the pitted defects with a minimum overwrap of 4 layers of Dragon QUAD-UHT composite system. 4 layers of Dragon QUAD-UHT composite were also applied to extend over the adjacent PCP/GRFE coating to provide a seal between the repair and the coating.
REPAIR METHOD
The substrate was prepared (excluding the identified defect area) using an MBX machine to gain a surface profile to SSP.SP11. All surface defects within the immediate repair area were repaired 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 4 layers of Engineered Dragon-QUAD-UHT composite and allowed to cure until a minimum of 74.5 “Shore D” hardness was achieved.
