GB262920A - Improvements in and connected with pumps - Google Patents

Abstract

262,920. Walker, J. R. Nov. 30, 1925. Regulating or controlling.-The discharge pressure of a centrifugal pump 1 is maintained constant or regulated at will by the introduction of a small quantity of fluid under high pressure into the inlet of the pump. The nozzle 5 of a manually adjusted needle valve 6 is so disposed that the jet from it exercises an injector action on, the water in the suction main 3, thereby increasing its pressure and the pressure on the delivery side. The casing 8 contains a piston valve 7 urged into open position by a spring 9; the piston has a head 10 beneath which are ports 10<1> communicating with a conduit through the stem. A pipe 13 connects the pump discharge 4 and the casing 8. With the valve 7 at its maximum opening as shown and the needle valve 6 withdrawn to its limit, the maximum flow occurs from the pressure side 4 of the pump to the nozzle 5. An increase, in delivery pressure depresses the piston 7, partially shrouds the ports 10<1> and diminishes the flow to the nozzle 5, thus acting to keep the delivery pressure constant. In a modification the controlling valve 17, Fig. 2, is of the double beat type with branches 15, 16 connected to the delivery and suction sides of the pump. The valve spindle 18 carries at its upper end a piston 21 in a cylinder open at the top to the atmosphere. The pump delivery side is connected to the pipe 24 and the pressure acts against the spring 23.