It also shorten remarkably the refilling time. And can protect the LPG gas from over-filling and can be used for recovery of residual LPG remaining in a storage tank. The pressure in which the LPG is transferred is at normal condition unlike the tank-to-tank method, which any gas leak may result in explosion.
A white fume of LPG gas can occur during gas skid filling operation. However, the white fume is mostly gas remains in the nozzle gun hose. The adapter safety-check valve is intended to prevent overfilling of the gas bottle. It is a one-way valve that allows LPG to be pumped into the bottle. Gas can't sprout out, because the filling gun is screw tightly to the gas cylinder valve preventing gas from escaping through.
Modern LPG refilling now has digital scale inserted with gas pump dispenser.