Selector relief valve assembly

摘要

A dual pressure relief valve selector is formed by a Y-shaped tubular body having an inlet port at its stem position connected with a vessel or a line to be monitored. Each leg of the Y-shaped housing is connected in fluid communicating relation with a safety relief valve. A spring and fluid flow biased open flap valve and valve seat is contained by each leg of the Y-shape adjacent the inlet of the respective relief valve. A pinion journalled by the housing moves a rack to and fro between the flap valves for normally maintaining one of the flap valves in closed position and isolating the relief valve downstream from the closed flap valve.