1-1/4" spud directly into small radiator?

Parker_Heath

Hi Guys,
Due to new space limitations just picked up a good used (steam) radiator which is a bit smaller/shorter than the one that currently is in use. It came with a 1" spud threaded into a 1-1/4 -1" bushing. I have taken out the old spud and bushing and am left with a hole for a 1-1/4" fitting in the new radiator. I would like to keep the old 1-1/4" valve (which still works and would difficult at best to replace) and fit a new 1-1/4" spud into my new smaller radiator. Is there any reason not to thread a new spud directly into the new radiator without a bushing? (isn't a bushing essentially just a reducer?) Thanks for your thoughts.
-Parker

Danny Scully

Yes, and no. Spuds are not universal, so while there is no reason you couldn’t screw it right into the radiator, it likely won’t seal properly on the old valve.

JUGHNE

Do you have the old spud from the original valve?
New spuds and old valves may not match. They can look really close but the threads of the union may not seal. Sometimes will strip out one or the other threads.

New valves come with a matching spud. They are usually a little shorter in height then old.

The old valve will come off with persuasion. PB blaster and long wrenches. Or you can carefully cut/grind the brass female part enough to allow it to unscrew. Preserve the riser threads.

Parker_Heath

Thanks for your thoughts above. I have yet to break out the old radiator...My intent is to gently remove the original spud in the existing/old radiator which mates to the old valve without distorting it. I guess if I bugger it up, in spite of PB Blaster, Kroil, and anything else I can try, I'll just have to spring for a new 1" valve and spud and hope I can unscrew the old valve off the steam line and add a reducer to the riser.

JUGHNE

Is your riser 1" or 1 1/4"?
It is not a bad idea to use an 1 1/4" valve.
Your bushing on the riser may give you that 1/2" of needed height for a new valve to fit. You do not want to reduce on any horizontal pipe.

Do not push the riser down. It is better to pull it up if needed.
You can shim the rad up with blocks or checkers as needed.
Air vent end must be higher than valve end.

Parker_Heath

The riser is 1-1/4". The swap to a 1" valve will add the height of the bushing and I can raise the new radiator the same amount. And yes, I know not to lower the riser and change the pitch of the pipes in the basement...condensate does not travel up hill back to the boiler very well.... Thanks again for the advice.

PinkTavo

I have seen the "matched set" comment quite a few times. Can anyone explain why spuds and valves don't have a universal thread?

Danny Scully

Well @PinkTavo, because, they don’t same is true of a union.

Jamie Hall

PinkTavo said:

I have seen the "matched set" comment quite a few times. Can anyone explain why spuds and valves don't have a universal thread?

They have a universal thread. What they don't have is the matched faces of the union. In fact, all unions have matched faces, which seal solely because they are matched.

Which is not to say that if you are using high quality parts, one male half union may well seal, at least under normal pressures, with a female half from another. Then again, it may not, which is annoying...

JUGHNE

We have to remember that the old valves/spuds could be 80+ years old.......a few decades farther back than that simple pipe threads and their fittings had to be obtained from the same company... not interchangeable.
The first wax 78 RPM records would not interchange between players. You had brand X records you had to have brand X player.

PinkTavo

Thanks for the answers Jamie and Jughne!