When this split case pump, at an Australian regional water authority, was removed from service for maintenance, it was discovered that the internal coating was failing. This lead to the exposure of the pump’s substrate to corrosion. Also, there was a visible crack in the pump lid.
The flange surfaces were protected with tape in order to insure there was no damage during the two phase abrasive blasting surface preparation. The first phase revealed substantial corrosion damage.
The pump was left wet for 24 hours to allow impurities to leach from the blasted substrate. The pump was then abrasive blasted a second time with angular steel grit to achieve a class 3 level of cleanliness and a profile of 75 microns. The first layer of CeramAlloy CP+AC was then applied using a trowel and brush.
While the CeramAlloy was still tacky, a topcoat of CHEMCLAD XC was applied. This ‘wet-on-wet’ technique will insure all the layers will cure as a monolithic composite.
After the curing process was complete, the protected area was first tested for thickness then spark tested at 3,000 volts. The minimum thickness of 600 microns was easily achieved.