A raw water pump in service at a combined cycle gas turbine (CCGT) power station, required a programme of refurbishment and corrosion protection, in order to prolong its service life.
Upon arrival at our workshop, the pump was stripped down and both the casing and impeller were abrasive blasted to the required cleanliness standards. The casing was then pre-machined to accommodate the coating process.
Plasmet HTE was then applied to all internals, 2mm on the casing and 1.5mm of the impeller. Plasmet HTE is a hardwearing, slip-free, three-pack, solvent-free polyamine cured epoxy screed. This coating is resistant to strong concentrations of sulphuric and other acids. It is ideal for areas requiring abrasion (and chemical) resistance. It has been used in cyclones, chemical process vessels, sugar beet pulping drums etc. Plasmet HTE is also useful for building up damaged areas of pump impellers and casings where impact or abrasion are prevalent.
The items were thickness and spark tested to 27Kv and 17KV respectively to check for holidays.
During the refurbishment process, bearing and gasket seals were replaced and the impeller was dynamically balanced. This was all completed before the pump was reassembled for dispatch and re-installation, to ensure the full protection against corrosive seawater.