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Pressure question

That is a pretty severe test of your Hartford loop height and your low water cut off.

That simulates a sudden major leak in the system return. The closed gate valve keeps the water in the boiler, while you flush the return with water, and eventually with the steam behind it.

Be careful



  • JM_2
    JM_2 Member Posts: 108
    If a pressuretroll

    is set a 1/2psi cut in with a differential of 1, is it safe to assume that pressure in the entire one-pipe residential steam system will never be above 1.5 psi? Assuming the pressuretrol is working properly.
  • ed wallace
    ed wallace Member Posts: 1,613

    the answer is yes but only if pressuretrol is working properly the gauge my not be reading correctly

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  • JM_2
    JM_2 Member Posts: 108

    I assume that my gauge is faulty because it reads close to 14psi. But i am having second thoughts about that. I have added a flush device on the return according to the advice in steam problems section "You install a gate valve on the return line, just before it enters the Hartford Loop. Right before the gate valve, install a tee with a full-size, full-port ball valve." However even without closing the gate valve if i open the ball valve there is a tremendous blast of steam. perhaps this is due to the pressure drop causing the condesate to quickly turn to steam. I gues i ill just swap the gauge.
  • Steamhead
    Steamhead Member Posts: 16,719
    John, check the pigtail

    below the pressuretrol. If it's plugged, the pressuretrol will not stop the burner if the pressure gets too high. This could cause a dangerous over-pressure situation.

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  • JM_2
    JM_2 Member Posts: 108
    Gauge is bad

    I took the gauge off and it was totally plugged, after cleaning it and cleaning out the tap for it it seems to read right. I will replace it tomorrow and check the pigtail on the pressuretrol. i wont open the return flush with out closing the gate below it again although when i did the wate in the glass didnt budge. I know my Harford loop is not conected correctly, it connects about 8"-10" above the water line, not two inches below.
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