If butterfly valve will be installed inside manhole, what is the best coating for this application to protect the valve from corrosion,do we need to paint this valve with epoxy. as I think the humidity inside chamber is very high so can we consider it like submerged application or we can consider it like exposed or buried. what I need to know what is the best recommended coating inside closed manhole ? 1- polyamide epoxy - for submerged application 2- Alkyd enamel with primer - exposed application 3- Tape coating - buried application Sometimes valves in pits must be AWWA certified, which IMHO means substandard valves designed by a committee, but the law is the law. Sometimes valves in trenches are laden with aggressive solvents. Composite valves are excellent for chemical resistance. They, in general, do not conform to AWWA, and there are solvents that attack the plastic components. There is a best valve for every application, and the composite valves are vastly superior for some applications. Other applications may be better served by different valves or different materials.

MORE NEWS