What is this Trane Vapor/Vacuum Part?

Harry_6

I just looked at a 1926 Trane vapor/vacuum installation today, and am perplexed. I saw original radiators with no traps, just what is apparently a normal union elbow on the outlet. It looks like the non-valve end of a hot water radiator, but it obviously isn't. So far, I haven't seen many radiators, but none had traps. So what am I looking at? It resembles a Kriebel system, but these elbows have "Trane" cast on them. Are there some kind of "orifice" valves? Or is there something special about these union elbows? Otherwise it's a perfectly normal system with a cylindrical Trane condensate return, Trane main vacuum vent, etc. So what am I looking at?

Steamhead

Those are special return elbows Trane used before thermostatic traps. They do much the same thing as a trap. Get this book:

https://www.heatinghelp.com/store/detail/the-lost-art-of-steam-heating-revisited

and you'll find them in chapter 15.

Harry_6

Thanks, good to know I'm not insane. A copy of the book is on its way.

mattmia2

Obviously in a vapor system if you have steam reaching the outlet of the radiator something is wrong.

Harry_6

I wasn't sure if the valves were some sort of graduated or orifice valves, and if any had been replaced with standard valves I'd need to do orifice plates.

mattmia2

the trane vapor valves can be identified if you look closely but they aren't as obvious as most other styles of vapor valves

Jamie Hall

The valves are somewhat special. However, if I recall you can still get vapour system valves — not Trane, but they work just as well. Supply House, I think. They aren't cheap…

But the old ones are probably fine. They don't break. It's only a prblem if some genius has replaced them with regular valves.

In the meantime — get the system pressure down if it isn't already. No more than 8 OUNCES cutout.

delcrossv

https://forum.heatinghelp.com/discussion/comment/1820587#Comment_1820587

Mepco.

https://www.mepcollc.com/product_category/regulating-valves/