Radiator air valve no longer fits snugly in the threaded hole

scottdoughty

I have a two pipe steam system and a wrought tube radiator. The air valve just spins around and won't tighten properly, resulting in constant steam leakage. I have tried using a 1/8 in. brass nipple with a coupling to accept the air valve, but the threads won't hold. I need a plumber with experience in solving problems like this to repair it for me. Can anyone recommend someone? I live in Cambridge, MA.

Abracadabra

Could use a helicoil insert or some JB Weld and retap it.

Why do you have an air vent on a 2-pipe radiator?

Fred

Two pipe systems typically don't have vents on the radiators. Anyway, most of us drill and tap the hole to accept a 1/4" to 1/8" bushing.

ChrisJ

Fred said:

Two pipe systems typically don't have vents on the radiators. Anyway, most of us drill and tap the hole to accept a 1/4" to 1/8" bushing.

This is what I'd do.
McMaster Carr has nice nickel plated 1/4" to 1/8" NPT bushings that work good.

KC_Jones

Post a picture of the rad so we can see both connections. If it's true 2 pipe system it isn't supposed to have vents at all. There is a 2 pipe air vent system and the picture will tell us which one you have.

Mad Dog_2

Uh...oh...this is how that radiator valve in the Bronx probably blEw off. No good. the first thing I would try history clean the thread a little bit with a tap and then try a black nipple in the hall and see if that's loose. ,if it's still wobbly, retap To a a quarter inch thread. don't take any chances Mad Dog

scottdoughty

Thanks for your comments. I believe my two pipe steam radiators do not have traps, so the vents are necessary to get rid of air. My first time posting to this site. I'd like to attach pics, but I don't see a button to do that. I like all the ideas presented. I think I'll drill it out for 1/4" and tap it, then use a 1/4-1/8 bushing. Should work, and is pretty straight forward.

Any cautions I should be aware of when I drill it out?

Fred

Just take your time and keep your drill and tap level and straight. Use the right size bit.

Sailah

If you don't have traps on your 2 pipe system why would the air go through a tiny air vent vs the 3/4" pipe on the radiator outlet? Do you have orifices or something similar?

When you post a message there is an icon right of center that looks like a dog eared piece of paper. That allows you to post pics.

Koan

Sounds like you should have someone look to see how the piping is done as well. Two pipe systems usually do not have radiator vents. It may be you have traps of which you are unaware, or someone installed a vent where one should not be.

Might be best to do nothing until you can post a picture.
To post a picture click on the icon that the blue arrow points to in the menu above immediately under the words
"Leave a Comment" 3/4 from the left as indicated in this picture.



Have you ever drilled and tapped a hole before? If not, maybe you can find a mechanic or a friend who has some experience to do this.

Sailah

scottdoughty

Thanks. That's the way I plan to approach it.

scottdoughty

I've drilled and tapped holes before, but it's been awhile, and perhaps never on a tube. I feel confident about it though. I don't know about the no air valve on two pipes systems, but I will mention it to my plumber. He's been schooled on steam systems, and he's never said there shouldn't be air valves. I think they've been in place for nearly 100 years with no problems. I've been in this house for 29 years with no problems until this ill fitting air vent reared its ugly head.

ChrisJ

I thought there were a few 2 pipe vented systems early on?
@Dan Holohan

Jamie Hall

Ah... I wouldn't guarantee it, but the photo sure looks as though you could indeed be looking at one of the early two pipe with air valve systems... valves at both ends and an air vent... they do exist.

ChrisJ

Jamie Hall said:

Ah... I wouldn't guarantee it, but the photo sure looks as though you could indeed be looking at one of the early two pipe with air valve systems... valves at both ends and an air vent... they do exist.

What are you, Santa and the M&Ms?

Double D

Two pipe air vent systems.

Koan

sounds like drilling and re-tapping is the way to go. Drill slowly being careful to hold 90 degree angles with some lubricant. Try to let as little of the the lubricant as possible get into the radiator. Get a good quality tap. Like @Fred said---take your time.

scottdoughty

Thanks Fred. I've got the air valve stabilized with a 1/8" nipple with a coupling, but I know it is only temporary. I will drill and tap it in the spring when the weather is not severely cold just in case I screw it up and have to call a plumber to replace the radiator. I appreciate your suggestions and I will cover all of them very carefully. I already bought a new 7/16" bit and a good 1/4" tap from a plumbing supply store for the job. I'm confident, albeit cautious.