Radiator Valve Help

SteamySwede

Hey Guys,

This will be the first of what I'm sure will be many posts and I look forward to joining this community.  Some of the radiators in my new (old - 1920's) house have an odd tab that sticks down and they only turn about 1/8 of a turn.  Sometimes after turning that small measure, they seem to close and won't reopen.  Can someone help explain?  See photo.  Thanks in advance.

gerry gill

sometimes the valves

have internal or external travel limiting devices that allow the valve to close but only to open to a certain degree..don't know from the picture if thats one of them..how do the radiators heat? it could also just be a steam cooked stuck valve also..

Steamhead

That looks like a Vapor system

which was the Cadillac of heating in its day and is still one of the best out there.



Some of these valves can be rebuilt. Were yours made by Trane?

SteamySwede

2-pipe / limited travel

If "Vapor" equals 2-pipe steam, yes it is.  I wasn't entirely sure if there is more to Vapor systems than that or not. 

Yes, a limited travel mechanism is exactly what it feels like.  A couple have felt as if they snapped shut (spring mounted valve seat?) and were heating very well before.  Now, when I twist them that minor turn, they barely warm any longer as if valve is only partially open.  Very odd. 

They are made by Hoffman I see, and have an area marked Open and Shut divided by a raised boss but valve is not routinely in right area to be in other spot and won't turn there. 

Thanks for any additional insights. 

Steamhead

They're either spring-packed

and the packing has probably gotten stuck on the stem, or they're packless, using a bellows to make the seal. Either way, I'd first take them apart and clean them, then lube them with some sort of high-temp lube.



If they can't be fixed, Tunstall makes rebuilding kits for a lot of these old valves- go to  www.tunstall-inc.com .



Did Hoffman make the radiator traps on your system too? If not, what brand are they? Does your system have a "Differential Loop" in the piping near the boiler?

SteamySwede

Thanks

Thanks Steamhead - I had no idea that valves existed like that.  Hoffman no longer appears to make them so I'll check out Tunstall. 



My traps are mostly Hoffman 17C it appears.  A few Cashin 12 (one I've repaired with a Tunstall insert).



As for the differential loop, I'm not sure.  I do have a Hartford loop (I think).  I've included a pic of the boiler setup if helpful.  Thanks again.

Hap_Hazzard

Maybe the picture is misleading

but that cardboard box looks a little too close to the draft hood.