Leaking Convector Union

TwoTones

I know there is a lot of info about leaking unions, but under my convector, the threads on this small piece(not a plumber)  have disintegrated on the union side and where it goes into supply pipe.  I tried tightening the union which made it worse.  You have to look at picture so see what I am talking about.  

    It looks like this “piece” of pipe is prob rusted on good where it goes into the supply pipe.  I am handy so I am wondering if this is something I can fix myself or do I need a plumber. Not sure if it’s a spud that needs to match valve.  Since it’s before the shutoff  valve I don’t want to mess it up and not be able to use my heat….  Going to cost a small fortune just for a plumber to look at it…. I tried alittle plumber tape on the threads of union with no luck….  The valve itself does not leak at all… 

TwoTones

Closer picture, that is an elbow coming out of floor…

Jamie Hall

That is indeed a spud which is half the union, the other half being on the valve. You may be able to fix the leak by separating the halves of the union and making sure that both sealing faces -- in the valve and on the spud -- are perfectly clean and shiny and without any scratches. Do NOT use anything stronger than a dish sponge on them. No sandpaper. No emery cloth. No steel wool. Etc. Then mate them. Some folks like a very very thin smear of pipe dope on the mating faces. Some like a very thin smear of dish soap. Some don't use anything. Make sure that the union really mates. They are not intended to take up any misalignment -- either lateral or angular. Then tighten the clamp nut, but only hand tight plus no mor than a half a turn with a wrench. If it doesn't seal with that, it's not going to seal.

TwoTones

Yeah I tried cleaning and tightening with alittle soap. No luck, I am guessing I am gojng to need a pro to replace that valve and spud?  I know that they are usually each made for one another…

TwoTones

Is this hard to change?

JUGHNE

You have the advantage that the spud is screwed into a coupling. Usually it is in the radiator and can be a chore to remove.

The coupling could just be unscrewed and replaced by new for new spud.

The valve body can be unscrewed from the pipe it is on.

Finding a valve with the exact dimensions might be the battle.
Many new ones are shorter and in your case that is the horizontal measurement to the pipe.

Otherwise just a "10 Minute Job".....

TwoTones

Thankyou @Mad Dog_2 for the expertise that actually solved my problem.  Turned out doping the crap out of the union mating surfaces and threads and then killing it tight with a wrench when tightening was the only thing that actually worked. I tried everyone else’s methods….   Much appreciated! 

Mad Dog_2

Awesome!  Like I said..whats the worst thats gonna happen? New Valve?  Mad Dog 🐕