What is this?

Dan C.

Two pipe system in a school. There are convectors in all the classrooms snd they each have on of these in the supply.

Ironman

Motorized valve?

PinkTavo

Old pneumatic actuator? Our local Jr. High still uses pneumatic valves...though it is not a steam system. Check out if there is still a compressor operating and what kind of stats are in place for the zones; if any.

JUGHNE

I would guess pneumatic also. If no air applied they would open completely for full fail safe (over) heating.

Grallert

That looks like a Johnson Streamline Union Angle with a Johnson #2 "Sylphon" operator.I have a bunch of then here at my facility.

Dan C.

What does it do? All clasrooms have convectors with these on it. Hallways have radiators and don't have them. Basement classrooms have steam baseboard elements and don't have them either.

Dan C.

It also has what looks like a pilot tube on it that goes into the floor. Not sure where it goes from there.

JUGHNE

Do you see any evidence in the building of an air compressor?
Small tubing (probably copper) runs for air supply.
Thermostats that might have been installed in the classrooms would control the air pressure applied to this inlet valve, modulating the steam feed into the convectors based on inside temp.
Some convectors may have had fresh air introduced into the class rooms, also controlled by a pneumatic system.
The hall ways and basement may have a zone valve for that area.
If the air system is gone and not in use the steam valve would most likely open to 100% without control in that area.

mark schofield

if you could clean the dust off the small white tube, it could be a small copper 1/4 od tube for pneumatic control. what is the name stamped on the black fitting?

Dan C.

It is the Johnson Syphlon as JUGHNE mentioned. There is no compressor in the building that I know of. If the compressor is not hooked up, is there any reason to remove these or can they stay?

JUGHNE

If there is no longer an air system in use how do they control the temp in the building?
What problems do they have that you are there?

Grallert

If there is no compressor and control that valve would be open as it is a normally open valve and requires a small amount of air pressure to close it. Are the convectors always hot? Maybe out of control hot? There is a copper bellows inside the cover of that actuator that fills with air pressing down on the valve stem controlling the steam flow

JUGHNE

Great picture, pretty old day/night system looks to be still in use!

Fred

Beautiful @Grallert !

Grallert

It hadn't been used correctly for years but with a little adjusting it's back in the game. Has a buzzing relay valve but intermittent. I wish there were still parts for this. I think this is from 1925 when the building was completed. I have another "modern" Honeywell control from 1956 in the addition, it has an annoying little air leak. Slowly but surely putting this place back in shape and learning a ton. Most of that ton I learn here from all you guys.
Thanks

JUGHNE

I service a 1961 school with a Powers Day/night system, It too was the Cadillac of the day. (Electronics/electromechanicals of that time were not available to do the modulation needed, from what I understand).
What parts do you need? I have had the all brass Powers D/N Tstats rebuilt, for about 1/4 the cost of new. They were the standard of the day.

Where is our original poster.....Dan C? He has an interesting project going on here. Unfortunately it is a school and a steam system like this is usually neglected/cobbled up almost beyond belief/repair. (It's not the Gym, ya know, so go figure).

Dan C.

I'm in Boston area. I need to go back and look at this again. I guess there is a compressor that he forgot to show me. Most of the rooms with the convectors don't get hot enough. This is the biggest issue that he needs fixed.

Grallert

If those convectors aren't heating enough and they're clean I'd be looking at the air pressure at the operator head (sylphon) this is controlled by the thermostat of a pressure switch inside the cabinet. which controlled by the main control which gets it's air from the compressor. Depending on the spring in the actuator that final pressure is quite low, maybe 3-5PSI? I'm still learning my way around these early operating system, Pneumatic systems in general. So I'm am no authority here but these are some things I've picked up.

This is the modern control. The twoway switch has a slight air leak.
This is a the buzzing relay on the Johnson control, it has two ports.
I've been sending the old thermostats to Edgemont Precision Rebuilders for rebuilds. Good company. They can rebuild my antiques to new. Most of my thermostats are T460's and 461's

JUGHNE

Dan C, if the lack of heat is consistent in most classrooms then if this has day/night setback capabilities that part of the system may be stuck in the night mode (set back). If you look at Grallerts' first picture there are the gauges for day/nite pressures.
14 psi day and 22 nite. Then there is some means of time clock to switch pressures.....simply put you could be stuck in night setback. (also maybe outdoor reset control?)

The little system I work on has a manual day/night switch.
The pneumatic system controls only the convectors for me.
For my classrooms to get more heat the system must be set to the low daytime pressure (14 PSI on the system)
My hallways and other baseboard heaters get heat all the time.

There is a lot more to it than that, but IIWM that is the first place to look.