Why is this happening !
Has anyone experienced this before or know why this might be happening! More importantly what can be done to prevent further occurrences.
Exposed metal parts of the impeller have been coated with copper which is collecting on the pump shaft seal faces as particles, causing them to breakdown the vapour barrier and leak. The treatment water quality has been tested by a specialist and is said to be good with slightly raised copper levels and low on molybdate but generally clear and free of sedimentation, the water temperature is around 80 C. and the system is mainly iron pipework with copper heating battery’s in the AHU’s and parts of the boilers.
The pumps are run from Variable speed controllers and the pumps are connected to the existing pipework by rubber flanged anti vibration seals, the current solution has been to extend an earth cable from the pipework flange across the rubber joint to the motor flange to reduce any potential voltage difference induced by the motor.
Senior Electrician at Corrigenda
9 年I think the rubber anti vibration couplings should be bridged with a conductor to ensure that the pump isn't acting like an anode.
Managing Owner of IntelliChange
9 年Sounds like you have inadvertently set up a copper plating cell.- while not solving the problem you might be able to put a negative electrode into the system which will preferentially attract the copper out of solution.
Sales Director at Flexiheat UK
9 年Paul, Do you have any Brass Valves, or components on the system ? are they DZR ? I've seen dezincification leave a copper coating previously. The usual suspects of High O2 & CO2, stagnant or slow moving water are usually to blame.