HVAC Waters

copper pipe corrosion

One normally thinks of copper as a stable, rather non-corrosive metal. Copper plumbing used for domestic hot or cold water lasts for years. In fact, until PVC and CPVC water pipe became available, copper plumbing was "top of the line".

Unfortunately, in instances copper pipe has been in service for only a year or two and failed. Water leaking from the outside turns of elbows is often the first evidence of failure. This is usually due to "impurities" or trace alloy metals in the fitting dissolving, leaving "copper sponge" behind. 

Contributing causes are: soft water, high water temperature, high flow velocity. Obviously, softened, circulating domestic hot water loops are prime candidates. Avoid zero-hardness soft water. Lower the water temperature to the minimum needed at the point of use. Lower the flow velocity so return water is at least 10 degrees lower than supply temperature.