Propane tank gauges

[RobA]

I have two 120-gallon propane tanks connected together which supply my house and emergency generator. Each tank has it's own gauge. Since they are connected together should they read the same? Or does the propane flow only in 1 direction and, therefore, 1 tank can be more full than the other? Currently 1 tanks says 20% and the other 80% (full).

 

[Country Geek]

Since the propane in your tanks is under pressure, I assume it only flows in one direction, out.

 

[Mendonsy]

80% is the level that they typically fill the tanks to (at least here). Kinda sounds like you are only drawing fuel from one tank. If both valves are open then they must have put some device in the line to isolate them.

 

[SandburRanch]

Is the valve on both tanks open? Can easily be overlooked. Lightly tap on the gauges with your pocket knife to see if the gauge bounces back to the original position. Are the 2 tanks the same temperature? One in the sun can have a higher temperature and pressure than a shaded tank.

 

[Deere Dude]

Chances are the connection between the two will only let gas go from one tank at a time. When one tank is empty it will automatically switch over to the other fuller one, so you can change out the empty and still have a supply in the house.

 

[Stimw]

An accurate propane gauge is actually measuring the liquid in the tank not pressure.
They do this with a float system in the liquid like gas/diesel tanks.
You can buy the temperature sensitive strips that will read the level of the liquid.
Because the liquid temp will change slower than the metal tank these will read the level.

 

[dave1949]

I used to have two identical tanks that were piped together. They never equalized. They would move in tandem though. If one had 60% and the other 50%, after use they would both decrease by about the same amount but still be 10% different from each other.

I think the internal pressure in the tanks would be equal regardless of how full they are?

 

[Mendonsy]

It probably has something similar to this:
automatic changeover regulator

 

[RobA]

Lightly tap on the gauges with your pocket knife to see if the gauge bounces back to the original position.

Bingo. The gauge on 1 of the tanks was stuck.