Cast-iron ceiling flange on old one-pipe steam system

JWoodoff

This is a question that is strictly cosmetic in nature. The single pipe risers on the one-pipe steam system in my 1909 apartment building were built with one-piece cast-iron floor and ceiling flanges. The floor flange stays in place by gravity, or has holes to be screwed to the floor, and the riser slides through it as it expands when hot. However, the ceiling flange has a side set screw to hold the flange against the pipe. This means that the flange has to be set well below the ceiling when the pipe is cold, so that as the pipe expands it doesn't destroy the plaster ceiling. In my living room, one of these pipes runs right through a coved ceiling and plaster ceiling molding, meaning it has to be placed well below the ceiling level in order to avoid hitting these features. Is this really the way this setup was originally designed, or am I missing something? It seems as though the flange should be fastened to the ceiling so that the pipe can slide through it as it expands and contracts, but there is no way I can see to fasten it like this. There is a soft metal sleeve that runs through the ceiling that the riser slides through, but there seems to be no way to afix the flange to that, either. Thanks for any insights!

Fred

That sleeve should have dropped down enough to slip the ceiling flange over it and then tighten the set screw to the sleeve. What is above the ceiling, another floor or an attic space? I suspect over the years, the pipe may have pushed the sleeve up. Is the sleeve loose enough that you can get a grip on it and pull it down enough to slide the flange over it? It may also be that the decorative wall and ceiling cove prevented the correct installation.

EBEBRATT-Ed

Are you sure the riser has not sagged for other reasons like a missing or loose hanger in the basement? In a short run of a riser you shouldn't have that much expansion. You should be able to secure the ceiling flange say a 1/4--3/8 below the ceiling when cold and not have an issue

JWoodoff

Thanks for your responses. There is an inaccessible attic space above my floor. The total run of the riser is about 40 feet. There is definitely a good 1/2" of movement; I will check the basement pipes to see if anything is amiss, but unlikely. You can see the sleeve in the photograph. It is quite thin and flexible; I don't know that tightening the set screw against it would be sufficient to hold the heavy flange in place. Tightening the screw could easily push the sleeve against the pipe, defeating its purpose. I tried to pull the flange down; I'll try again with pliers, and if I can lower it I'll try tightening the screw against it, but as I said I'm not sure that will work. But it is interesting to know that is how it's supposed to work, even if it doesn't in this case.

Fred

@JWoodoff , You may find that that sleeve has a screw hole in it and that set screw is actually a screw that went into the sleeve.

JWoodoff

Thanks, Fred. I will look for it.

ChrisJ

Looks like you would see around 5/8" expansion from cold to hot on a 40' pipe.

JWoodoff

Chris, that sounds like just what I am getting.

I was able to pull the sleeve down a bit, but I measured the diameter of the sleeve and the diameter of the flange at the point where the set screw is, and the sleeve is way bigger, so the original set-up could not have included screwing the set screw against the sleeve.

What I will have to do is plaster around the sleeve and maybe paint the sleeve white so that when the pipe is cold and the gap shows, it won't be so noticeable.

Thanks to everyone for your comments, and if there are any other ideas for a better way to fix this, please tell.