In a system of 4 SPP pumps, taking measurement for flow and efficiency identified that three were operating at such a reduced level that overhaul was viable on the grounds of improving efficiency. The pumps were new in 1970 and apart from minor maintenance had not been overhauled since installed.

Levern was selected to carry out the removal, overhaul, re-installation and re-commissioning and Arc was specified as the efficiency coating system. The work was carried out during 2001.

Post overhaul tests showed that the pumps were now more efficient with a greater flow rate than when new.

‘Top Hat Section’
After removal all old paint, rust is removed from inside as well outside.

After initial blasting, an inspection was made. Original casting and machining marks were still visible.

2 coats of ARC S2 were hand applied to a thickness of 700 µm

Impeller and Wear Rings
Although there was some surface corrosion on the impeller surface there was no measurable wear.

Likewise the clearance on the wear rings was still well within tolerance.

Grit blasting of the main body again showed no measurable wear.

Both the impellers and pump volutes were coated with ARC S2. Original wear rings were re-used. New bearings and Sterling Mechanical Seals were fitted and the pumps re-assembled.