Jadnashua
Retired Defense Industry Engineer xxx
PVC water pipe is different than PVC drainage pipe...you must select the proper one for the intended application. Some PVC is designed to handle upwards of 400psi, whereas, drainage stuff maybe 50psi or less.
Ideally, you get rid of all galvanized supply pipe...it's a problem waiting to happen. One hassle is that when you thread it, you expose the iron after cutting through the galvanization. A cut end is not galvanized, either, so water will start to degrade it (i.e., rust it). It can work in say a HVAC heating system, because it's a closed system, and once any oxygen that may have been in the water is creating rust, it stops as it reaches an equilibrium since there isn't any more oxygen to create rust. A leaking system, or potable water, always ends up with fresh oxygen in it, and that will cause the pipe to rust.
FWIW, rusting and dielectric degradation are two different things and can occur together, speeding up the eventual problem.
Ideally, you get rid of all galvanized supply pipe...it's a problem waiting to happen. One hassle is that when you thread it, you expose the iron after cutting through the galvanization. A cut end is not galvanized, either, so water will start to degrade it (i.e., rust it). It can work in say a HVAC heating system, because it's a closed system, and once any oxygen that may have been in the water is creating rust, it stops as it reaches an equilibrium since there isn't any more oxygen to create rust. A leaking system, or potable water, always ends up with fresh oxygen in it, and that will cause the pipe to rust.
FWIW, rusting and dielectric degradation are two different things and can occur together, speeding up the eventual problem.
