Abstract: A cylindrically hollow housing has an inlet at its upper end and an outlet at the lower end. A valve seat having a primary bore extending axially through its center is located in the housing dividing it into an upper and a lower chamber communicating through the primary bore. A ball is freely located in the upper chamber and an operating lever extends axially through the outlet opening. The lever has a flanged head closing the outlet. The lever is resiliently biased in a first position wherein the head closes the outlet and is movable into a second position wherein the outlet is open for the passage of fluid. The valve is arranged so that when the lever is in the first position the primary bore is open for fluid flow and when the lever is in the second position the ball occludes the primary bore.