A leaky tank valve is rare. SO WHY TEST FOR IT?  

    If the user is religious about bleeding the hose, but still experiences spitting and/or orange shooting flames
    (commonly called the flame thrower effect) after lighting the Hot Head Torch, a TANK VALVE LEAK is the most
    likely cause.  The flame thrower effect is scary but not especially dangerous.  All fuel immediately vaporizes at
    room pressure, which happens once the fuel reaches the flame cup.  The fuel vapor will burn up before landing
    on anything, but fuel additives and tank lubricants can leave greasy droplets because they are not flammable.  
    The Liquid fuel will hammer on the torch valve as it passes through the valve causing rapid wear to the valve.  If
    fluid fuel is allowed to blow through the torch repeatedly without being addressed, the torch valve may
    eventually leak as well.

    Tank valves always leak INTO the hose, so there is never the telltale gas smell.  The primary symptom of a Tank
    Valve Leak is spitting when the Hot Head is first lit.  

    But if you are smelling even a tiny amount of gas, the Hot Head valve may be compromised and your torch
    should be bubble tested for leaks.  If the torch leaks, it should be retired.  See the bubble testing document for
    directions to test the Hot Head for leaks..

    A Tank Valve Leak will pressurize an empty hose between uses, even though the tank valve is OFF.  But don’t
    worry, any UL approved, US made hose will hold full tank pressure indefinitely.  The torch end of the hose is
    clamped shut and will hold full tank pressure indefinitely or until the Hot Head is attached and opens the hose.  
    The tank valve tests should be done with healthy, functional torch.

    Here is the test:
    Day 1:
    1.        If the Hot Head is in good shape its valve is working normally, proceed.
    2.        While the torch is still producing a flame, turn off the tank, but not the torch. Allow the torch to consume
    all remain fuel vapor in the hose.   This is the standard method used to “bleed” the hose between beading
    sessions.  A tiny amount of fuel vapor may still be in the hose after the flame has gone out. It is minimal and will
    dissipate rapidly in a well ventilated space.
    3.        After all vapor is gone from the hose, turn off the Hot Head Valve.   
    4.        Leave the Hot Head attached to the Hose.
    5.        Wait 24 hours.

    DAY 2: You are checking to see if the hose has pressure in it even though the Tank Valve has been OFF,
    confirming a Tank Valve leak.

    This is really important!   Do NOT turn on the tank or the test is void.   

    1.        Prepare to light the Hot Head as usual.  
    2.        Have the match lit, in place and ready to light the torch.
    3.        Turn on the torch to light it like you normally do. .  
    a.        If there is pressure in the hose, you will hear hissing and may smell gas.  
    b.        You may even be able to light the torch.  
    c.        If there is a lot of pressure, it’s a bad leak.  

    Note: If you don’t hear a hiss and cannot light the torch with the tank valve still closed, you don’t have a tank
    valve leak.

    4.        Don’t turn on the tank valve.  Allow the Hot Head to consume all the fuel remaining in the hose from the
    5.        Turn off the torch but leave it attached to the hose and tank.   

    If the tank valve has a leak, DON’T WAIT.  Take your tank with the hose and torch attached back to your gas
    supplier and ask for a replacement tank and fresh fuel.  If you wait the hose will charge up again.

    How do tank valve leaks happen?  Some brands of tank valves are more likely to develop leaks spontaneously,
    but this is very rare.   Any fuel tank should remain upright, or nearly so, at all times – that means carrying,
    storing, transporting and using a fuel tank in the upright position.   All fuel tanks develop corrosion over time
    and/or the fuel put into a tank may carry in debris of one sort or another.  When the tank is allowed to lay
    sideways, the fuel sloshes and can deposit debris in the tank valve. The debris stays in the valve like a high tide
    line even after the tank has been righted and the fuel is gone. The debris is solid and if it lodges in the right
    spot, it can prevent the valve mechanism from closing completely - so a leak develops.

    This is how the physics work, if you’re interested.  The fuel vapor seeps through the supposedly CLOSED tank
    valve into the empty hose.  After 24 hours, even a slow leak will allow the hose and the tank to reach
    equilibrium.  That means the hose will have the same pressure in it as the tank does. (~ 160 PSI at room
    temperature - no matter how much fuel is in the tank.).  The fuel vapor in the hose will condense into liquid fuel
    until the ratio of liquid fuel to vapor is the same as in the tank.  When the tank is nearly empty, there will be only
    be a little fuel in the hose.  But when the tank is nearly full, the liquid fuel in the hose can be enough to actually
    block fuel vapor from moving through the hose to the torch.  Instead the pressure will force the liquid fuel out
    through the torch, and the flame thrower effect happens.     

    A tank valve leak is noticed most often when you have a full tank for two reasons.  
    a.        Ratio of fluid to vapor for a full tank is more fluid, less vapor and the hose will have the same ratio. The
    more liquid fuel in the hose, the more likely the spitting will occur.
    b.        If you SWAP tanks when you get fresh fuel, then you’ll have a different tank and a different  tank valve,
    which may have a leak. So you’ll notice the leak right away.  If you haven't noticed a leak by the time the tank is
    nearly empty, you don't have a problem.

    This test is safe because any UL approved hose would always have full integrity under full tank pressure, even
    without the torch attached.  

    The contact information for Ed Hoy’s is:

    Ed Hoy’s International
    27625 Diehl Road,
    Warrenville, Il. 60555