Thread: galvanized piping

.......

Similar Threads:

• Galvanized Pipes on Hot Water Heating Systems
• copper piping corrosion
• A/C Evap Drain Piping Trap
• Galvanized gas supply line and fittings.
• Unknown piping.

Scott, when I see corrosion on the exterior fitting of a plumbing line (supply or drain line), I advise my clients the corrosion is an indication of a leak at the area. It may not appear active now but corroded areas tend to self-seal themselves for a little while before leaks eventually reappear. Plus, galvanized pipes corrode from the inside out and should probably be replaced.

Scott its worth mentioning, but be cautious about how you report it. You can certainly have corrosion without a leak. Galvanizing is a way to provide a form of cathodic protection to the pipe. The galvanizing (zinc) is a sacrificial anode. Its purpose is to corrode, so as to provide protection to the steel. Electrolysis can occur when you have an anode, a cathode and an electrolyte. The electrolyte can be dampness caused by sweating of pipes. I cant tell by the photo, but you may also have two disimilar materials (copper and steel) causing the corrosion. A lot of times you see corrosion at the threads due to the threads being field cut and not receiving any protection. Basically when they cut the threads they destroyed the zinc coating.
Products like ZRC exist for this purpose.

Old galvanized pipes are prone to leak from the inside out, but usually this shows up on the pipes serving the hot side first. As far as replacement goes, I wouldnt make any kind of recommendation like that. I would just report what I saw and let the client make the decision of replacement is required. There are some companies doing internal liners on steel pipes with pretty good success.

From what I can see on the picture the gal. pipe in question is the water supply lines and this could possible be caused by condensation. It did not look like a leaker but the picture was a little blurry, or my eyes are getting bad not sure which.

Scott,

Unless there is water on the surface of the pipe (not condensation) I'd be cautious about saying that there's a leak. I would say that the pipes in your pic are still ok. But it's prudent to let the client know what to expect from galvanized pipes. Personally, I don't report on "minor" corrosion. My experience has been that when the pipes get to be about 40+ years they can become problematic. I let the client do the math and analyze what potentials may be present.

Looks like a leak to me.

'Rust from probable leak, no previous proper repair visible, thus a previous leak may have gone un-repaired, un-repaired leaks which seal themselves will typically leak again at some time.'

Something to that effect gets the point across:
1) it looks like a leak
2) which means it most likely was leaking
3) but it may have self-sealed
4) because no one made a repair on it
5) and it will probably leak again

I would say it more directly, as though I know it was leaking (I am sure it was), but it can be toned down to 'looks like a leak to me', which is like saying 'it's leaking - I think'.