Case Study

Four butterfly valves in service at a UK power station required refurbishment and protection against corrosive cooling water.

The Solution

Two of the valve bodies were in a poor condition with several areas of corrosion and material loss evident near the flange faces. The valve bodies were shot blasted to remove any loose material and the damaged stainless steel valves were weld repaired. Plasmet HTE was applied by hand to the internals of the bodies, HTE provides excellent chemical and abrasion protection in testing service environments. A final coat of Plasmet EB added further protection against cavitation corrosion. Plasmet ZF was applied to the external surfaces.

The valve blades were found to be in good condition requiring flash blasting to remove an existing coating before Corroglass 600 was applied to achieve a dft of 1.5µm. The coated valves were re-assembled and the shafts were secured using shrink fit shear pins. The valves were then pressure tested to 30psi before being prepared for transportation back to the power station for reinstallation.

Power Generation