This pump is driven by a 1.25mW motor.  It was taken out of service as the efficiency had fallen to below 70% of that when it was new.  There was also concerns that the steel fabricated body was worn to an unacceptable thickness in places.  The repair was expected to return the pump to at least 95% of new and give a new life of over 10 years before the efficiency dropped to an level requiring a further overhaul.  Previous overhauls had lasted about 5 years.

The edges of the diffuser blades were cut back and new metal welded in to provide a structure.  The Volute  was blasted to SA 2.5 and measured profile was 106 microns.  The item was then solvent washed with Chesterton 204 non-flammable solvent which leaves no residue.  

Over 100kg of ARC 897 was applied to reform the profile of the various parts.  This was finished with ARC 858 which was also applied to the volute parts where significant abrasion had taken place. The complete body was then sprayed internally with ARC S2 to provide a low coefficient of friction, but hard wearing surface.

The pump is now pumping at 104% capacity compared to when it was new in 1966.  With this increased capacity, the return on investment (ROI) has fallen from an anticipated 3 years to less than 18 months.

Anticipated life of the repair is at least 10 years, with a drop in performance being dramatically reduced over this time as tolerances are maintained and internal energy consumption reduced.