2-pipe Steam- no traps

Joe Blanks

Came across a 2-pipe system today that was a little unusual to me. No traps anywhere. Each rad's return comes down into a dry return in basement, and there is an air vent at the end of the return main. This return main ties into a tee at the end of the steam main. This end of the return has a check valve before it ties into the end of the steam main. The 2 furthest rads (2nd floor) each have an air vent on the radiator. I noticed in 'The Book' that Dan says the only way to not use traps is to drip every rad, main and riser into the wet return. Is it acceptable to use this check valve? Looks like the original install...

jumper

if it works

if it works it works. What sizes are the supply and return at each radiator ? So long that air gets out, radiators fill with steam and give off heat.

Steamhead

That's probably an Orifice system

in which orifices at the inlet valves keep the steam from reaching the radiator return connections. This does the same thing as traps do.



Take some pics of some radiators, and a close-up of both sides of an original radiator valve. Post them here so we can have a look at it.



The check valve isn't needed any more- run both drips below the waterline and into a Hartford Loop, and you should be OK