Pipe Size

steamymcsteamface

I have a one pipe steam system in my house and need to move one radiator 90 degrees. After considerable attempts I cannot budge the pipe so I figured I'd just add a 90 degree elbow. Measured the diameter of the existing valve and got what I thought was 2". Bought a 2" fitting at local plumbing supply it was too big. Exchanged for a 1.5", it was too small. They do not have a 1.75".
Searched the web for a 1.75" pipe fitting, no luck.
What are the sizes of old (house built 1915) steam pipes?
Thanks for any assistance

nicholas bonham-carter

Post a picture of the part you wish to attach to. A steam valve will have a standard size opening on the inlet, screwed onto the riser, and then a proprietary size union nut thread on the outlet.
Bronze, or brass valves will not rust onto the steel pipe, and a combination of heat and chemistry should make it possible to turn them.
Many valves, and fittings have the size marked on them, so can you see any markings on the part?—NBC

steamymcsteamface

Here's a pic...... don't see or feel any markings. These connections are pretty siezed. When we remodeled the bathroom I had a professional plumber and a contractor trying with heat and large pipe wrenches to budge one with no success.

nicholas bonham-carter

Those are the proprietary threads which will only fit each other.
The only other solution now is to cut the valve off, and use a new valve, and spud into the radiator. Unfortunately, removing the old spud may not be easy either.
To add insult to injury, the replacement valve may have a different height than the old, causing difficulty in lining the two pieces up.
Maybe you can rent this:
https://www.ridgid.com/us/en/compound-leverage-wrench
Which exerts tremendous force on the joint.—NBC

steamymcsteamface

NBC,
Thanks for the information, that piece of equipment looks like it might help budge the valve however I heard/read that much torque can collapse the pipe. Have you had any experience with this type of situation? Besides heat, any other tricks/tips to get the valve loose?

steamymcsteamface

Also, what do you mead "proprietary" Was there different fittings used in the past?

KC_Jones

That is a union on the valve, it is not a standard pipe fitting thread. In addition spuds and valves are a matched set, so if you replace one you must replace the other.

JUGHNE

To extend this 90 degrees, you need the spud out of the radiator to connect back into the valve union. After that you use standard black pipe fittings to connect your radiator.
The spud was installed with a spud wrench. On occasions they can come out with that tool. Often the brass ears inside will break off.
Then the next attack would be to lay the rad down and try a pipe wrench. I insert/wedge a smaller pipe tightly inside the spud to keep it from collapsing. The pipe wrench needs narrow jaws because the nut is crowding the jaws. If that fails then cut the very end of the spud off to get the nut out of the way and wrench away.

Next attack:
Can you raise the pipe coming thru the floor?
If so a new valve is usually shorter than old, but if you get enough lift you may have a match up.

Then you cut the side of the old valve with a grinder or hack saw in two places. The brass valve cuts easy just be sure to not cut into the floor pipe threads. Once there is even one cut in the valve it may unscrew.

EBEBRATT-Ed

If you don't want to crush the pipe and damage it get a grinder with a cutoff wheel. Make 3 cuts on the valve 90 degrees apart in line with the riser pipe. Go as deep as you can without cutting the threads. Then cut straight through the valve 1" up from the bottom of the valve. Then you can easily remove the brass pieces and clean up the threads and install a new valve.

Then cut off the union nut on the radiator tail piece. Then you can get a wrench on it.

steamymcsteamface

Good stuff thank you all.
So your are saying that the threading on the pipe coming through the floor where the valve is attached and the radiator threads where the spud attaches are "standard" and I will be able to buy a valve and spud that fit?

nicholas bonham-carter

Yes

EBEBRATT-Ed

Yes. I have done quite a bit of this "old work" I used to be intimidated by it but it just take some patience and the right tools and some time

steamymcsteamface

Follow Up.....
I got lucky and after a night of soaking in penetrating compound the valve fitting budged loose. After 25 years I finally got to use that extra large large pipe wrench that took up a lot of room in the bottom of my tool chest. I cleaned the threads put heavy duty thread tape on and re positioned so that it faced the way we wanted it.
Again thanks for the great knowledge and sage advice.

nicholas bonham-carter

That is so lucky! Thanks for the follow up.—NBC