Case study – Weld repair on a 10 inch water injection system
Integrity issue
The welds on two sections of pipework on a 10 inch water injection system constructed from super duplex steel were suffering from internal corrosion coupled with manufacturing defects. The weld defects were through wall. To reinstate the integrity of these sections of pipework it was proposed to use a FutureWrap Glass/HT composite repair.
Design
The design of the FutureWrap Glass/HT repair was to both seal the through wall defect and strengthen the pipework assuming the internal corrosion had completely removed the weld. The design parameters were; pressure 18.5 bar, temperature 700C, design lifetime 20 years. An HT repair was used as the pipework surface temperature during application would be 700C implying that rapid curing of the repair during installation would be an issue. The repair design resulted in a thickness of 6.5 mm (8 layers) of FutureWrap Glass/HT composite repair with an axial length of 650 mm.
Installation
The installation steps are shown in the photographs. The surface preparation was to ST3. Rapid resin curing was controlled. Full QA/QC measurements were made to demonstrate that the FutureWrap repair was applied in accordance with ISO 24817.
Summary
Welds on two 10 inch sea water injection super duplex pipework suffering internal corrosion coupled with manufacturing defects were repaired using FutureWrap Glass/HT composite repair. The repair was completed within 3 days reinstating the integrity of the pipework.
