Integrity issue

A CSU drilling mud tank, 2.8 meter diameter, which had been out of service for several years was to be re-commissioned. There were several holes in the main body of the tank as well as in the pipework attachments. The cause of these through wall defects was internal erosion/corrosion. 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 several Futurewrap Glass/LT composite repairs on the tank main body and associated pipework.

Design

The design of the Futurewrap Glass/LT repair was to seal and strengthen the tank. The design parameters were; pressure 0.4 bar, temperature 200C, design lifetime 20 years. It was assumed that the composite repair would withstand the applied loads and seal without any allowance for the remaining wall thickness of the tank.  The design resulted in a thickness of 5 mm (6 layers) of Futurewrap Glass/LT composite repair with an axial length of 260 mm. The repairs on the tank main body were applied as patches.

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 drilling mud was repaired using Futurewrap Glass/LT composite repairs.  The repairs were completed within 3 days reinstating the integrity of the tank.