High pressure gauges are required to be able to test a propane system for leaks. They are generally mounted in a tee fitting which, in turn, is connected directly to the tank fitting.
• 1-5/8" face reading to 300 psi
• 1/4" male NPT stem
Heavy on the technical side...
What Does That Pressure Gauge Tell You?
Thinking back to your high school chemistry class — because of the physics of your propane tank always containing both liquid and gaseous propane, the pressure inside the tank remains virtually constant until all the liquid propane is gone and the tank is functionally empty.*
For this reason - and unlike gas-only SCUBA or CNG tanks - the pressure on the gauge cannot be used to determine how full the tank is.
The pressure gauge is only there to perform periodic leak tests to check the integrity of your system.
We recommend that leak tests be performed every time the tank valve is opened, and at least every two weeks when the valve is left open during extended use.
How Much Propane Is Left In My Tank?
To determine how much propane is left in a tank, you have to weigh it and then subtract the known weight of the empty tank.
Or, with a translucent composite tank, you can just look at it to see the level of the liquid propane in the tank. This feature, alone, probably goes a long way toward explaining the huge popularity of composite propane tanks.
* The pressure in the tank will vary somewhat with changes in the ambient temperature.