Help identifying this. never seen one before

BenitoMN · January 31

We don't have a ton of residential steam in the Minneapolis/St Paul area but we have enough that it's worth learning and I've been very busy with it this heating season since the only other company I was aware of that would work on it lost their 1 steam person. I've never seen one of these before. The homeowner hasn't been in the house long and didn't even know it was connected to the system. I'm not sure if it's a steam actuated electrical switch, or electrically actuated steam valve. The right side has a 1/4" tube connected to the 2" steam main. I don't know where the piping coming out of the left side goes as the basement is finished and I can't follow the piping. The other 1/4" tube is connected to 1/2" pipe and disappears into the ceiling and the other end connects to the main further to the right. There are only 2 things I know for sure: 1) it's steam related, 2) the black knob is set to On.

Long Beach Ed · February 1

What do the radiators look like?

Is it a single pipe system or two pipe system? Vents on the radiators? More than one thermostat? What's the era of the house and what is the boiler pressure set to?

Looks like a basic 1950s solenoid valve to me, with a older switch to open and close it though I can't imagine why it's there.

The 1/2-inch pipe in the wall attached to another tube suggests there may be another one behind the wall with the rotary switch perhaps operating one or the other.

Remnants of a partial Iron Fireman Selec-temp modulating system? They operated on higher-pressure steam via 1/4" and 1/8" tubing.

tim smith · February 1

Velly intellesting, will be interested to see who knows what it is. Steamhead (Frank) or one of several will know it. Not me!

mattmia2 · February 1

the 1/4" tube is to keep condensate from stacking up behind the valve when it is closed. at least that is usually what it is. does the valve connect to something besides the 1/4" tube? otherwise some sort of vent or vacuum system.

i bet the rotary switch is in series with some sort of automatic switch so that when the rotary switch is off it is turned off and when the rotary switch is on it is automatically controlled.

BenitoMN · February 1

Replying to Long Beach Ed.

Single pipe steam system. Radiators are standard sectional cast iron radiators. 1 thermostat for the whole house. House is from the 1930s, the original oil line is sticking out of the concrete floor but has been abandoned and now is an approximately 20-25 year old 125,000 btu natural gas fired boiler, natural draft into a lined masonry chimney. Boiler pressure is set to 2psi with a 1.5psi differential. Every radiator has a vent along with a single main vent at the end of the main just before the pipe drops to the wet return.

I was originally there yesterday because the customer was complaining about the master bedroom radiator valve leaking, after some further questions they were also having water hammer at that radiator as well. I found they had closed the valve partially because they wanted the room cooler and thought the banging was normal. I explained you can't do that on 1 pipe steam and told them to leave the valve fully open and then upsold an adjustable vent. A further inspection at the boiler revealed 2 leaks on the wet return, 1 before the Hartford loop and the other at the boiler return connection. They have an auto feed and would have flooded the basement when the pipe broke. I returned today and repaired the leaks. It was a good thing too, I put the pipe wrench on it and barely applied any pressure and the wrench poked a hole right through it and the nipple collapsed in on itself. I also replaced the radiator valve and installed a Legend brand adjustable vent and showed them how to adjust the vent for a cooler room. They're happy the radiator no longer bangs

Long Beach Ed · February 1

So it's no Selec-Temp system.

Mattmia is suggesting it's controlling a room or rooms as a zone valve, which makes sense. As he asks, what are the connections to the valve? We see the pipe on the back that goes to the 1/4" copper tube and pipe on front that comes off a 1-1/2" or 2" main. You mention a left pipe. Is there another coming off the valve that we don't see?

Sounds like you solved the customer's troubles just in time. Ninety year old wet returns rot out just as you found. Let's see if we can solve this zone valve mystery…

Steamhead · February 1

I bet it's an old water feeder. Have you traced out the wires going to it?

EBEBRATT-Ed · February 1

Steam off the main going to a humidifier?

There is some other tubing running along the steam main that ties into a 3/8 or 1/2" galvanized looking pipe.

mattmia2 · February 1

https://forum.heatinghelp.com/discussion/comment/1839432#Comment_1839432

knowing where the other end of about 10 things here are would help greatly.

delcrossv · February 1

https://forum.heatinghelp.com/discussion/comment/1839432#Comment_1839432

That's what I'm thinking. That's an electric valve hooked up to a humidistat somewhere. Galvanized pipe probably runs to a duct or grate in the living space.

Intplm. · February 1

Hmm. I'll take a guess. Maybe a Fire-o-Matic safety? An oldie for sure. @BenitoMN Does it say Beckett on it anywhere? Any sort of writing?

pecmsg · February 1

That says "ON", so it is an old style switch. What it controls you'll have to carefully follow the wires.

Can you get a better picture from under?

ratio · February 1

See if there's an arrow on the valve body. If it's pointing towards the steam main, I have no clue what it might be doing. If it's pointing away, it's diverting steam to do something. Steam pressure isn't likely to be it, unless the system dates to before they standardized on low pressure. With that ¼" tubing, it wasn't something that used a lot of steam. Steam humidifier looks like a good bet on the face of it.