Case study - 8 inch sea water return line
Integrity issue
An 8 inch sea water return line was suffering from both internal and external corrosion. A temporary repair had been applied to the line to seal the through wall defect. A long term solution was sought and therefore an engineered FutureWrap repair was proposed. To reinstate the integrity of this section of vertical, overboard pipework it was proposed to use a FutureWrap Glass/LT composite repair, overwrapping the existing temporary repair.
Design
The design of the FutureWrap Glass/LT repair was to strengthen the pipework and seal the through wall defect. The design parameters were; pressure 12 bar, temperature 500C, design lifetime 10 years. It was assumed that the composite repair would carry all the applied load. Although overboard a FutureWrap Glass/LT repair was used as the pipework after surface preparation was dry. The repair design resulted in a thickness of 6.1 mm (8 layers) of FutureWrap Glass/LT composite repair with an axial length of 12300 mm.
Installation
The installation steps are shown in the photographs. The repair was applied off ropes. The surface preparation was to ST3. Full QA/QC measurements were made to demonstrate that the FutureWrap repair was applied in accordance with ISO 24817.
Summary
An 8 inch seawater return line suffering both internal and external corrosion was repaired using FutureWrap Glass/LT composite repair.
