CLIENT
Nuclear Power Station in South Africa
APPLICATION DATE First application 1988 and Maintenance Review 2013.
SCOPE OF WORK
Repair minor mechanical damage on the volute where
the back plate was removed. Recoat back plate 100%. Abrasive grit blast damaged areas to SA 2½ and apply Corroglass 600-Series to a minimum DFT of 1.2mm, spark test to 10Kv DC.
PRODUCTS
Corroglass 632 at 1.5mm plus 652 blue topcoat for
original coating work AND Corroglass 632, 602 screed plus 652 blue topcoat for casting wear rings in place during repair.
“POSITIVE’S”
These seawater cooling pumps form an integral part of the cooling system of the nuclear plant. The client removes the back plate annually for statutory inspection of the wear rings, after which Corrocoat rebuild the coating at the interface between the back plate and volute. The stuffing box is also built up internally with Corroglass to a thickness of +-5mm, after which it is machined down to tolerance.
During the service life of continual internal seawater exposure with a low hydrochlorite dosing and high flow, the coating has shown no deterioration, and zero under-cutting, even at the exposed coating edge at the flanges and threaded sockets.
Based on the performance of Corrocoat products over many years the plant obtained engineering approval to replace the OEM rubber lining in the large heat exchanger water boxes with Polyglass, and a long term contract was placed on Corrocoat to maintain the linings in the entire seawater cooling system.
