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One way check valve on return steam line

Was notified of a blocked return line (in a single pipe steam system) by a series of very small gremlins with very large hammers. Finally found the problem with a blocked one way valve (And I mean finally) that was buried behind a wall in a short stretch of vertical pipe. That pipe joins a T where a second return meets the final return leg. Not sure why it is there. Can it be eliminated? This is small a two floor house with only about 13 radiators (and of course an oversized boiler -Utica 225peg)


  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    The check valve was probably put in keep water from leaving the boiler, during over-pressured steaming. Remove the flapper, and see if the problem goes away with a properly cleaned, and adjusted pigtail, and pressuretrol.
    If the boiler loses water still, then look for part of the return whose height is slightly above the normal waterline. This can hide the water, even at low pressures.--NBC
  • Jamie Hall
    Jamie Hall Member Posts: 23,275
    Don't you just love it when they hide things like that? And yes, as NBC says -- the valve can be eliminated or just taken out of play by taking the clapper out if it is that type. Just do make sure the pressure is correct -- no more than 1.5 psi cutout.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
  • garfieldsimons
    garfieldsimons Member Posts: 13
    Valve only covered 1/2 the system. And was a shut crud trap. And will now be history and I expect so will those wee folks with the jackhammers.
    Thanks for the help.