Radiator steam valve replacement

tkos115

Hi all, I'm new to this site (and steam heating system). I bought a house that uses steam heat. Unfortunately almost all the steam valves on the steam pipe to the radiators are either leaking, or no longer turn. I'm looking to replace them but wasn't sure if there is any special tools I'll need, or any tips anyone has. I did buy a spud wrench though. I assume from the pictures that the new valves come with the pipe piece that the spud wrench is needed for?
I'm pretty mechanically inclined as I do engine rebuilds and other types of mechanical of repairs so I believe I can tackle this project with some guidance.


The steam radiators appear the be brand stamped as ARCO, however i'm not sure how old they are though.


Thanks for your help, and sorry if I sound ignorant about all this.

Jamie Hall

Before you get into the rather interesting job of putting in new valves -- which does mean getting the spuds out of the radiators, which isn't quite as easy as it looks -- check and see if the valves are repairable. In many many cases both the problem with leaking and with being stuck can be traced to the packing in the bonnet which seals the stem. This bonnet can be removed rather easily in most cases, and the packing replaced. It's a lot easier than persuading a spud to part company with a radiator...

KC_Jones

As long as the valve is fully open (very likely) there really isn't much reason to worry about it working IMHO. For steam the valve should always be fully open and is really only needed if you need to remove the rad, during the winter, for an extended period of time. Personally I have found a few shade tree methods around that as the valve tend to not shut off anyway (seals are long gone).

As Jamie said I'd look at repacking the valves for stem leaks and leaving them alone otherwise. Full valve replacement in the entire house won't be a lot of fun.

tkos115

Unfortunately they appear to be leaking at the flange where the big nut tightens to the radiator. I did try cleaning the theads with a wire brush but it didn't seem to help. They looked pretty bad.

nicholas bonham-carter

I think you are referring to the Union nut. This holds the machined faces of the spud to the valve.
Clean both the surfaces, and examine them for dents, and gouges. Lube them with dish liquid, and reinstall. Rock the radiator gently as you tighten the Union nut.
Old valves can usually be repaired a lot more easily than replacing.—NBC

rwilson2526

I'm not a pro but I have changed all my radiator valves. #1 don't be tempted to leave the fitting with the union nut in the radiator because they look identical. I know you dont plan on it but you may be tempted. 2nd thing is not once did I get the fitting to spin out using the spud wrench. It just sheared off the little brass nubs that the spud wrench is supposed to grab on to. Best method I found was to cut off the union nut with an angle grinder and cut off wheel. Lay the radiator flat on its side with the legs facing away from you and put a pipe wrench with cheater bar on the fitting and push!

1Matthias

tkos115 said:

Unfortunately they appear to be leaking at the flange where the big nut tightens to the radiator. I did try cleaning the theads with a wire brush but it didn't seem to help. They looked pretty bad.

Try cleaning the mating surfaces of the union. The threads play little role in sealing, other than bringing the mating surfaces together snugly. https://2.imimg.com/data2/LT/MM/MY-936611/34-500x500.jpg (The mating surfaces are the bevels near the middle of the diagram.) I've used scotch-brite to remove major gunk (Painters + radiators = *!@!~@#), then 0000 steel wool to do this.