Forum Discussion

SCADAMAN29325's avatar
SCADAMAN29325
Explorer II
Jan 13, 2023

Leak down test on the LP gas system, leak detected.

Next I will be looking to see if I have any issues with LP Gas system. The stove, furnace and fridge appear to be working fine. I have not tested the water heater yet as I have it in the winterized mode.

From what I can tell, I need to put a pressure guage near the regulator, turn on the gas at the tank, then note the pressure, turn the gas off and hope the pressure does not drop. I should have done the leak down test first, before I tested the appliances, but I didn't know about it then and still made it out alive.

Could someone suggest a guage? I think I want to put it on the 4-port tee, maybe on the 1/4" inverted flare fitting. As someone suggested, I may want to rotate the T ports down to where the 1/4" port is pointing down.

Thanks!

Class C
  • enblethen's avatar
    enblethen
    Nomad
    Jan 13, 2023
    Gauge should be on the line beyond the regulator. My old Itasca had a gauge installed in the refer outside access.
    Soapy water is beast for the high-pressure side.
  • wolfe10's avatar
    wolfe10
    Explorer
    Jan 13, 2023
    A little difficult to tell from the picture, but it appears the regulator vent in in the long axis of the regulator. This is NOT the correct PN for a horizontal installation.

    The vent (quarter sized screen) needs to POINT DOWN.

    The place you bought it should have asked if it would be installed horizontally or vertically.

    Yes, this is a safety issue.
  • Thomas_NH's avatar
    Thomas_NH
    Explorer
    Jan 13, 2023
    The operating pressure for liquid petroleum or LP gas appliance is 10" - 11" of water column. Going above that pressure you can rupture the pressure regulators in the appliances. I shut off the gas valves and test the lines at 5 PSI for 20 min. I'm a licensed gas technician.
  • ernie1's avatar
    ernie1
    Explorer
    Jan 13, 2023
    Thomas/NH- What does one do at high altitude when gas appliances don't want to operate? Is it ok to set the regulator for a higher pressure?
  • enblethen's avatar
    enblethen
    Nomad
    Jan 13, 2023
    11-inch column of water I believe translate to somewhere 1/2 PSI.
    Anybody know for sure?
  • Thomas_NH's avatar
    Thomas_NH
    Explorer
    Jan 13, 2023
    Running LP at high altitude is more a problem of getting the liquid in the tanks to flash-up to a gas. The regulator will do it's best to compensate, but if there is little pressure in the tank it won't work. Readjust the pressure is a bad idea for when you return to lower levels. Short-term heating the tank would work, long-term (stationary appliances) changing the orifices is what we do. You probably wouldn't like the way I heat the tanks; I use a torch (yes and open flame on the tank) and no I haven't blown up yet (I've been doing this job for 54 years). I guess you need to know how and where to put the flame.

    Yup, 12" WC is pretty close to a half pound, but that's a real pour way of measuring it.
  • GottaRunGottaCa's avatar
    GottaRunGottaCa
    Explorer
    Jan 13, 2023
    enblethen wrote:
    11-inch column of water I believe translate to somewhere 1/2 PSI.
    Anybody know for sure?

    There is 28 in. (27.68 to be exact) of water column in 1 PSI.
  • enblethen's avatar
    enblethen
    Nomad
    Jan 13, 2023
    My memory serves me that the gauge on my old rig was 0 to 1.5 psi.
    Had to turn off LP tank and look to see how much PSI dropped in 2 hours. Any drop was bad.
  • SCADAMAN29325's avatar
    SCADAMAN29325
    Explorer II
    Jan 14, 2023
    wolfe10 wrote:

    A little difficult to tell from the picture, but it appears the regulator vent in in the long axis of the regulator. This is NOT the correct PN for a horizontal installation.

    The vent (quarter sized screen) needs to POINT DOWN.

    The place you bought it should have asked if it would be installed horizontally or vertically.

    Yes, this is a safety issue.


    I found a pic of the old installation, so I need to rotate the regulator like this, correct? BTW, I did this (and learned that the input end has left hand threads). I don't want anyone else taking credit for my screw ups!

    I think someone mentioned this before and I thought they were talking about the 4-port T.


  • SCADAMAN29325's avatar
    SCADAMAN29325
    Explorer II
    Jan 14, 2023
    Back to the leak down test. I saw YouTube about using a clear plastic hose to do the test.
    https://youtu.be/QnlfQK-8qy4

    And this one explains detail about water column.
    https://youtu.be/SD1qcH_hNYY

    I'll let you know if I get blown up.

    Thanks!

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