Gauge is fitted between two end fittings through gland packing. The gauge is mounted parallel to tank so as to form a close loop causing tank liquid to seek its level in the gauge. The Gauge Glass is protected with ‘C’ channel. End fitting has built-in isolating valve, drain valve & vent plug.
Auto ball check facility is provided to prevent "liquid loss" from vessel during breakage of gauge glass. It consists of a capsule located within the gauge neck' and contains a ' ball which moves freely along its inner race between the stopper & orifice. During breakage, the pressure on 'ball' from gauge side will be atmospheric, whereas higher pressure from vessel side ("optg pr + liquid column") will cause the ball to move and block the orifice, to minimize liquid loss.