NIEDERDRUCK- RÜCKFÜHRVENTIL

摘要

A low pressure recirculation valve for cooling a centrifugal pump. The invention comprises a unitary valve casing divided into a first valve chamber and a second valve chamber, the casing having a first port for introducing fluids into said first chamber, and a second port for expelling fluids out of said second chamber, the first chamber having a recirculation port for redirecting fluids back to said centrifugal pump. A multiple piece check valve member situated between said first chamber and second chambers permits the flow of fluid from said first chamber to the second chamber and prevents the flow of fluid from said second chamber to said first chamber. A slidable valve stem coupled to said check valve member and extending through the first chamber moves the check valve member from an open to closed position. Means coupled to said valve stem biases the slidable valve stem and check valve means toward the closed position. A recirculation valve means operatively coupled to said valve stem opens and closes said recirculation port, said recirculation valve means opening when said check valve means is closed and closing when said check valve means is open.