I recently bought a house that has a 65 gallon LPG tank for the stove &
outdoor grill. I'm trying to determine how full it is. It has a pressure
guage that shows about 18 PSI at the moment. Given that the guage goes up
to around 100 psi, I'm guessing this ain't toooo full. Am I right, or can
you tell from the pressure reading?
No in theory the pressure is the same if there is any amount of liquid
in the tank...
When the liquid is all gone, the pressure of the remaining gas will
decrease as you use up the remaining gas.
The pressure of the liquid /gas combination will vary with
temperature, but not with the amount of liquid.
While the gas and not the liquid burns, it is still only filled to 80 % for
expansion due to temperature. If filled all the way and the temperature
warms up slightly you will vent the tank through the relief valve.
By design, approximately 20% of the interior space in all propane tanks, OPD
and otherwise, is reserved for expansion to safely accommodate the 1.5%
increase in volume that propane experiences for every 10 degree Fahrenheit
temperature increases. In an overfilled tank, insufficient space may remain
as the propane warms up, expelling gas and/or liquid forcefully through the
safety relief valve.
: I recently bought a house that has a 65 gallon LPG tank for the stove
: & outdoor grill. I'm trying to determine how full it is. It has a
: pressure guage that shows about 18 PSI at the moment. Given that the
: guage goes up to around 100 psi, I'm guessing this ain't toooo full.
: Am I right, or can you tell from the pressure reading?
Pour a kettle of boiling water down one side. You will be able to feel
where the level of liquid is by where the temperature gets cool. The
empty top will be warmer than where the LPG level is. Sometimes
condensation will form on the cool part if it is humid.
OK I'm an idiot. After looking at the web site for the propane company, I
realized the gauge doesn't read in PSI, it is a float gauge that reads in %
full. So the tank has about 18% of 65 gallons, or about 12 gallons. Should
be enough to get through the weekend, anyway ;-)
Thanks to all who replied.
Good, because I was just about to tell you that if the tank pressure was
REALLY 18 psi and the local temperature was above minus 10 F, then there
was no liquid propane at all left in the tank. <G>
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