copper for steam?

Anna Conda

Copper is okay for wet returns but should not be used for any runs that carry the steam. The coefficient of expansion of copper is much greater than that of iron, so the copper will expand and contract much more, putting a great deal of stress on the soldered joints, causing them to fail early. Iron does not expand as much and the threaded joints will absorb the expansion stresses. Copper sheds heat much more readily than iron, causing the steam to condense before it gets to the rads, leading to water hammer problems and insufficient heating. For peace of mind, stick with iron for steamside piping.

g rad

copper for steam?

own a small 6 flat in chicago,have to run steam line into storage unit for a store,have a vertical iron steam pipe that I can tee from,question is can I use copper type L for the new run,about 10 feet long,1.5 inch dia....system is a one pipe steam.thank you

lchmb

recommended

It is standard practice, and strongly recommended to use black iron.

kpc_5

i agree..

I would do the black iron...it may be more work but it will operate better in the long run. Also on't forget to clean/ skim the boiler after you do the work...all that oil will amke its way back to the boiler and give you all kinds of grief if you don't....kpc

Dave Faust

OK??? But why do manufactures use copper in steam to water heat exchangers?

Brad White

Because

it is a completely different application- fluid to fluid heat transfer.

Copper is a better conductor of heat than ferrous metals and is less likely to corrode in a way that adds fouling the way iron would. (For longevity I specify cupro-nickel or admiralty metal tubes, but the materials are still similar.)

In a steam to water heat exchanger, the steam is outside the tubes in the steel shell and the water is inside the copper tubes. This creates a mass which buffers the expansion forces.

Also the tubes are not soldered nor brazed but are compression swaged into the tube sheets. Each tube is a U-bend which is allowed otherwise to "float" and absorb expansion forces gracefully.