Case Study

Client

Shipping Company, UK.

Scope of Work

A Chief Engineer at a shipping company declared a seawater pump volute casing, to be most likely beyond repair. The casing had large areas of cavitation pitting, and had very thin walls at the discharge side. If a new volute casing was available, it would have to be requested via special order and would be incredibly expensive. It was deemed money may be better spent purchasing an entirely new pump. This would have a 16-week lead-time. As a third and final option, the ship’s superintendent suggested a coating service could be worth looking into, and so, he turned to Corroserve.

Products

Corroglass 600 series including lamination resin.

The Solution

Firstly, the pump rebate was pre-machined to accommodate the coating process. Areas not being coated were masked up and protected prior to abrasive blasting and coating. The internals were abrasive blasted in accordance with ISO 8501-1 to Sa2 ½ surface finish. A minimum surface profile of 50 microns was achieved. A complete blow down, sweep and vacuum clean then commenced. This was to thoroughly remove dust before applying the coating. A complete 100% visual inspection was then completed. Laminating resin was used to build up the damaged areas with extreme corrosion erosion. This included the cutwater.

Corrocoat Corroglass 600 series was applied, to a minimum DFT of 1.25mm. Due to the double cut water design, a flood and drain technique was used to ensure all areas of the internal were coated. A spark test at 17kV was then completed. Once the coating had cured, any surface protection and dress edges were removed.

The cost of the repair was a third of the cost of replacement, and the pump casing is estimated to last another 5 years in service.

Credentials

At Corroserve, we see countless pieces of equipment from clients, which are considered damaged beyond repair. Our engineering services and corrosion protection expertise, enable us to work with a multitude of clients to repair and protect their damaged equipment, at a fraction of the cost of replacement.