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One pipe steam????

Oh yes they do, you probably don't know they are there.

Look at the upper pipe tapping on the side of the rad opposite the supply valve. You might see what looks like a plug, but I'll bet there's an air vent in there. It's called the "In-Airid" and was made by the American Radiator Co. Here's a scan of the In-Airid section of the 1929 Ideal Fitter catalog.

Here's what I'd do: After a visual inspection and a successful test of all the safety valves and controls, fill the boiler in the usual manner. If it doesn't leak and you determine the boiler is safe to operate, you can fire it up, but be ready to shut it down immediately if required. I'd have several guys in different parts of the house and another at the circuit breaker panel to make this happen. Start firing for short periods and don't let pressure build up right away. Sometimes only a slight pressure will reveal a leak.

There's always some uncertainty when starting a boiler that has not been used for some years, but with reasonable care you should be able to handle it safely. But I must admit I've never actually done this- if anyone out there has more suggestions I'd like to read them too.

If the boiler is really that old, I'd consider just replacing it.


  • Timco
    Timco Member Posts: 3,025

    A customer of mine has a one pipe steam system, shut down for 10 years +. The rads have no vents...What type of system is it? Is there a way to fill the boiler and check for leaks or see why they stopped using it? The boiler is 1920's, forgot the make.

    Just a guy running some pipes.
  • will smith_4
    will smith_4 Member Posts: 259
    Good Get!

    Another possibility is that the original vents leaked, and someone replaced them with plugs...stopped the leaks, no? (What have they been doing for heat all this time?) Can you replace them with newer styles; are the drop away pressures comparable?
  • Steamhead (in transit)
    Steamhead (in transit) Member Posts: 6,688
    You'd have to

    drill and tap the rads in the usual vent locations and install standard vents. They don't make In-Airids anymore.
This discussion has been closed.


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