Integrity issue

A stainless-steel foam rectangular tank, 1.2 meter high, was suffering from cracking of the welds. The cause of these defects was combined manufacturing defects and external chloride cracking. A repair solution was sought to return the tank to service using an engineered Futurewrap repair. To reinstate the integrity of the tank, it was proposed to use Futurewrap Carbon/LT composite repairs over the damaged welds.

Design

The design of the Futurewrap Carbon/LT repair was to strengthen the tank assuming 4 mm loss of tank wall. The design parameters were; pressure 1 bar, temperature 400C, design lifetime 2 years. It was assumed that the composite repair would share the applied loads with the remaining wall thickness of the tank.  The design resulted in a thickness of 5 mm (4 layers) of Futurewrap Carbon/LT composite repair with a width of 255 mm.

Installation

The installation steps are shown in the photographs. The repair was applied off ropes as the pipework is elevated. The surface preparation was to ST3. Full QA/QC measurements were made to demonstrate that the Futurewrap repairs were applied in accordance with ISO 24817.

Summary

A foam mud tank was repaired using a Futurewrap Carbon/LT composite repair.  The repairs were completed within 3 days reinstating the integrity of the tank.