Propane Question

[Gary RVRoamer]

The long answer is that tank and gauge capacity is measured by the water capacity, abbreviated WC on the tank spec. Water isn't compressible and that's a constant & reliable measurement. Propane and other gaseous fuels are highly compressible and transition easily between gas and liquid, making a "gallon" a vague measure at best. The LP gas industry and the fire safety experts have agreed that propane tanks should be filled to only 80% of the water capacity, thus allowing for LP gas expansion. Many LP gauges have two scales, one based on the WC capacity and another for the propane. "Full" on the propane scale is the 80% level on the WC scale.

[Bigd9]

"...the takeaway is that a refill will never show 100% on the gauge..."


Actually, when I get the propane tank filled and the Overfilling Prevention Device (OPD) stops the flow, or liquid propane starts to vent from the fill vent valve, my Discovery does show full. It's all in how the gauge is calibrated.