Steam radiator with thermostat vent installed top of radiator fed with 3/4 pipe and 1/2 pipe on bott

pugdad

Any one seen a system like that 

EBEBRATT-Ed

Yes its a thermostatic radiator valve (TRV) with a remote sensor. The sensor is probably under the radiator.

Whats your question?

pugdad

That part I know It’s pipe size and location of valve at the top of the radiator that puzzle me

JUGHNE

Steam finds it's way down (all the way from the attic main) to the low pressure point at the bottom of the rad and into the rad trap.

Steam doesn't know up from down, just goes from higher pressure to lower pressure.

This is a typical top feed rad. Down feed supply from the attic. Has a drip trap below the supply pipe. Air vents added for a unique situation, so disregard for your scenario.

pugdad

Boiler and main in basement 

Steamhead

@pugdad , this is almost certainly a Vapor system. Vapor is a sub-class of steam heating that was designed to run at no more than 8 ounces or so at the boiler. It was the Cadillac of heating in its day, and is still one of the best systems out there.

The Honeywell-Braukmann valve shown does not vent air, but serves as a temperature limiter. It stops steam from entering the radiator if the room reaches the valve's setpoint. Air from the radiators exits thru the return connection, travels down the overhead return lines in the basement, and is vented near the boiler.

Are there any original radiator valves left in your system? Any weird-looking devices in the piping near the boiler? Can you find the vent on the return lines? Post some pics if you can- every Vapor equipment vendor had their own twist on the basic concept, and this will help us ID yours.

JUGHNE

Could you get a good picture of the 90 ell (1/2" return pipe) at the bottom of the rad where it exits the rad.
Are they all at the same end as the supply valve.