SAFETY VALVE FOR CHEMICAL TANKS

摘要

A safety valve comprising a valve body (4) defining a valve chamber (6). An inner tube (8) runs through the valve body (4) from an inlet (9) into an outlet (10). A seal is arranged in an inner tube (8) near the inlet (9). The liquid product enters the valve chamber (6) through the first set of holes (16). A third set of holes (20) are provided near the outlet end to allow the liquid product to exit the valve chamber (6). The third set of holes (20) have a smaller flow area than the first set of holes (16). The valve chamber (6) thus fills with liquid product and a float (22) arranged around the inner tube begins to rise, uncovering a second set of holes (18) in the inner tube. The second set of holes (18) have a flow area substantially the same as the first set of holes (16). The float moves between a full flow position in which both the second (18) and third (20) set of holes are uncovered and a reduced flow position in which only the third set of holes are uncovered.