Two Pipe System using One Pipe Radiator

Viggen1

Hello, I have a two pipe steam system from 1925.....everything seems to be working fine. The previous owners removed a radiator from the foyer and just capped the pipes. Since it is an odd size and in my area it is hard to find good condition two pipe radiators....can I use a one pipe radiator for this room? I would keep the return capped and just hook the inlet up with the valve and keep the steam pressure valve intact on the new radiator. Thanks!

Steamhead

Nope. The steam supply pipe is too small to handle the water trying to get back down. It will bang and spit.

Where are you located?

Viggen1

Really? I have Inch and a half intake pipe. I am in Northeast PA. Thanks

Steamhead

What size is the return pipe?

Viggen1

One inch return pipe

Steamhead

Take a pic of an existing rad and post it here. This may not be the usual setup..............

Viggen1

When I moved in,


the original radiator was removed and the pipes were capped below in the basement. See pictures. Intake is inch and a half and return is an inch pipe. The radiator picture attached in similar in size but in another room

nicholas bonham-carter

Are you sure the internal diameter is inch and a half?
Those pipes look smaller to me. Since the original piping is below, why not just remove the end plug of your new radiator, and connect it to the return below?
Too small a pipe will not make the radiator, or you happy. The difference in venting from two pipe serial venting to one pipe parallel will make that difficult to balance.—NBC

Steamhead

I thought so. This is a Vapor system. The runouts were enlarged, probably to keep the pressure drop down, but the steam riser is 3/4" and the return 1/2".

Try Olde Goode Things in Scranton. They probably have some radiators.