Steam Fin Radiator Pitch Question

jd2870

Hi all - I am renovating an addition on my home that is heated by a steam finned radiator that runs for about 20 feet (there is a 90 degree bend after 15 feet as it wraps across another wall). The radiator slopes about 4" in that 20 feet. It is the single pipe for both the steam supply and condensate return. I will be building a new cover for the radiator and it would be significantly easier for my purposes if I were able to reduce the pitch by a few inches. After looking into it, I believe that the minimum pitch is 1" over that 20" - but I was hoping someone could verify that under my specific circumstances (I'm not sure if the bend requires additional pitch or if the fact that that the whole thing is a radiator rather than a line makes any kind of difference). Thanks!

Jamie Hall

Fin tube on steam? Single pipe? You need all of that pitch. the 1" in 20 feet is for a riser or supply line, where there should be very little condensation. The condensing is occurring in the fin tube, and it has to somehow make its way back to the inlet...

jd2870

Many thanks on the reply - you don't think I can give any of that back? For purposes of functionality of the new cover, cutting even an inch out of that run would be a help. Thanks!

ethicalpaul

It shouldn't even work at all--baseboard and single pipe steam don't mix very well. I think you are lucky.

If you reduce the pitch, you risk gurgling/lack of heat/banging. That's what I've learned on this site.

nicholas bonham-carter

You could run a line from the end back down to the dry or wet return so that the steam and condensate would be moving all in the same direction.--NBC

retiredguy

Make sure that the finned tube radiation is at least 1-1/4" and better yet 2" diameter. I have had some success using 2" diameter steel finned tube on 1 pipe steam systems as long as the finned tube radiation is not too long and has a high pitch. I have seen too many jobs that a novice installer used 3/4" finned tube that would not work. my 2 cents

jd2870

Many thanks, the radiator (1.25" pipe) was installed decades before we moved (we moved 10 years ago) and it hasn't given us any trouble with hammer or getting hot etc. Ordinarily I'd leave well enough alone, except that part of the radiator cover will effectively double as a foot rest for a breakfast bar set up, and I'd like to keep it as low as possible.

dopey27177

Fin Tube Radiator correct a problem.

See the attachment.

This piping configuration Drains all the condensate from the heating element.

See the lower half of the return. The water seal is balanced by the incoming steam pressure. The key is to have sufficient height for the collumb of water to create a greater pressure than the incoming steam pressure.

Jake