Nature of defect
The 6” Tee with 4” branch had suffered from external corrosion close to the Tee. This resulted in wall thinning with 1.6mm remaining wall thickness. The client requires a composite repair to bring the line back up to its full design specification.
Solution
Metalyte Pipeworks produced a repair method with a minimum overwrap of 10 layers of Dragon-Quad-Std composite system.
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 the geometry of the line fully restored to its original OD using Herculyte resins. 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 10 layers of Engineered Dragon-Quad-Std composite and allowed to cure until a minimum of 74.5 “Shore D” hardness was achieved.
