Doing something wrong with steam radiators

TroyNY

So I'm a complete amateur with steam heating but I've been reading and trying to learn what I can. The I just replaced a supply valve on one radiator and changed our another to add a vent to one of my mains (it has nothing and apparently the entire system was just using the radiator vents this whole time) 

The problem I'm having is on both radiators after I put everything back together they're leaking from the radiator side on the valve nut. I'm obviously doing something wrong just don't know what. (Thought I had them lined up pretty good) 

Any tips tricks or advice would be greatly welcome

Danny Scully

Did you remove the old spud from the radiator and replace? 

EdTheHeaterMan

Danny Scully said:

Did you remove the old spud from the radiator and replace? 

The union type of connection from one brand of fitting or valve to another fitting or valve is rarely interchangeable. The part of the valve or elbow that is connected to the radiator is called the "SPUD" It has the union ring that fits over the valve threads. You will need a special wrench to extract the old spud and install the replacement valve spud. They are not very expensive.
https://www.supplyhouse.com/Bluefin-RVSW-Radiator-Valve-Spud-Wrench

JUGHNE

Did you change 2 valves?
Do not lose the new spud that came with the new valve.
Don't try to strong arm the old union nut onto the new valve threads.
That wrench Ed mentioned you will need to install the new spuds.
They seldom work for removing an old one.
The ears inside usually break off on the old ones.
Then that usually involves some sawing and chiseling.
Look for a U-tube for that process.
If you were handy enough to remove your old valves you can certainly remove spuds.

EdTheHeaterMan

Let's suppose you already knew that... and you already replaced both pieces of the new valve. In that case, your alignment is off or the union outer ring is cross-threaded over the valve threads. Confirm that your threads are aligned properly and use a 18" or 24" pipe wrench to draw the nut on the union closer. Sometimes rocking the radiator slightly to and from the wall, will help in the aligning and snugging operation.

Have a helper lift the radiator legs off the floor 1/2" by pushing it to the wall and lasting is back, at the same time you will take a 1/32 or 1/64 of a turn on the union nut. Each rock will get the union closer to mating and sealing.

Jamie Hall

I might add to @EdTheHeaterMan 's comment: make sure that the radiator is aligned as perfectly as you an before making up the union. Both angularly and up and down and sideways. The union is not intended to pull things into line. Also, don't be a gorilla with those wrenches.

Dan_NJ

Gordo covered it pretty well here

https://youtu.be/BZaTTAME88k

TroyNY

I have not changed out the spud. Video I watched mentioned it might not be necessary and I really really hoped I could get away with not doing that. But alright ordered the spud wrench. Also, because I'm new to this I didn't know pipe dope was a thing. So I'll try it with that. Thank you everyone for the help.

TroyNY

TroyNY

On the plus side I did actually get steam to at least get to the radiator for the first time 😁

Fred

@TroyNY , Why did you put that vent on that tall stand pipe? If you need to vent that radiator run-out, you could have just put that vent on the Tee at the bottom, that branches off to that shut off valve. Also, the vent on the opposite end of the radiator should be mounted in a tapping that is about midway up the radiator. Mounted at the top, like it is, steam may get to it and close it before all the air is out of the radiator so steam can fill the radiator.
I'm also not sure how you connected that shut-off valve if you didn't remove the spud.

JUGHNE

Could we get a close up of the valve connection for the tee connection with the ball valve?

I have put the B&J BM vent up that high on a fairly large system to avoid water passing.
Even at 4' there is a little water spitting before the vent closes.

TroyNY

@Fred basically I was aping a bit of what another hvac guy did except I added the 45' for water hammering (at a suggestion) and yeah I know that radiator vent needs some repositioning. As far as the spud goes, no flipping idea. Since this post I took all that apart added pipe dope put it all back together and rocked the radiator as I attached it. Went easy on the wrench but tightened it until it stopped leaking and that worked....

@JUGHNE yeah I'll get that close up

TroyNY

mattmia2

uhh...that bushing doesn't have a taper on the face like the union on that spud is supposed to seat in to. not necessarily even the same threads.

ratio

Good catch on that, @JUGHNE!

That certainly isn't the other half of a union on the valve, but if it's not leaking now I think I might just leave it until it is. While there is a tool to turn the spuds, it generally just shears the lugs off the spud when you try and remove one, so you'll end up cutting it out to replace it anyway.

TroyNY

@mattmia2 nope your absolutely right. Huh. Well somehow I got it to stop leaking so as @ratio says in going to leave it alone for now. I'll keep that in mind for the future though

EBEBRATT-Ed

Yeah, can't put a bushing into that spud

TroyNY

@EBEBRATT-Ed so what should I have used to make up the difference?

Fred

TroyNY said:

@EBEBRATT-Ed so what should I have used to make up the difference?

You should have used a correct steam valve and the matching spud that comes with it or, if you wanted to use that valve, you should have taken the spud out of the radiator and replaced it with a nipple, on both ends (radiator and valve) and a coupling in the middle.
The way you have it set up now, it will likely leak again and you may even get some banging or water spitting out of a properly located vent because the radiator is going to hold water as a result of the reducers you have the valve connected to. Means condensate has to build up in the radiator to the level of the smallest pipe, just before the valve.