FLUID STORAGE TANK RELIEVING VALVE WITH SURGE CONTROL

摘要

A relieving valve (10) for a fluid or liquid storage tank (12) to permit release of pressure from inside the tank as necessary. A piston (42) is movable within the valve (10) to open the same to atmosphere as pressure builds up slowly therewithin. Upon occurrence of a sudden or rapid pressure rise in the tank (12), such as when the fluid therein surges against the valve (10), a snubber assembly (58) in the valve is moved by said pressure rise to a partially closed position to impede the rate at which pressure can build within the valve (10) and thus increase the time before which the valve opens to atmosphere.