Galvanize pipes

Herve

I am currently in the process of replacing a section of dry return with a wet return on some residential steam piping. I would be interested in feedback on the following two items:

1) Is galvanized pipe ever used in wet returns in order to decrease corrosion caused by carbonic acid? Are there any problems with leaching of the plating and an impact on boiler performance?

2) The original system was likely installed several decades ago and the fittings appear much more substantial than the typical 150 psi malleable iron fittings. Is it possible/likely the original installer would have used 300 psi fittings to provide better corrosion allowance? Note that the pipe itself appears to be schedule 40.

Thanks for any insights you might be able to provide.

Bryan_5

Herve,
This is the Galvanized that I just replaced on my 2 pipe. Check out the thread Gate Valve versus ball valve.

Dale

Don't use galvanized

Zinc is really quite reactive and can flake off when in contact with boiler chemicals. The fittings may be steel forged, Lots of my old timer friends got them "free" from pipefitting jobs in chem plants and used what they had, if you do your low pressure replacements with shedule 40 black iron it will work fine.

Bob_19

Avoid

galvanized like the plauge.

Mike T., Swampeast MO

And not only in steam systems...

Galvanized WILL corrode and build up "crud" in water systems as well. NEVER "scab" black iron systems with galvanized!