Photo Gallery Series B: Corrosion Types And Conditions
For HVAC, plumbing, and fire protection systems, the most common piping materials are carbon steel, galvanized steel, cast iron, ductile iron, copper, and brass. Various forms of corrosion impact all such systems although the different forms of corrosion are relatively limited.
Evidence of corrosion activity are often quite obvious, such as the encrustation of rust and scaling deposits around the threads, or the obvious weathering at an exposed condenser water line – indicators that should prompt immediate repairs. Under deposit corrosion at a condenser water by-pass line, or erosion to copper pipe, on the other hand, provide no indication to their presence until a failure occurs. Pinhole failures at today’s galvanized steel pipe may appear within a year, whereas it takes about 80 years for dezincification to produce a failure condition to older brass pipe.
