Control apparatus for a positive displacement reciprocating pump

摘要

A positive displacement reciprocating pump for conveying a liquid or gaseous fluid is disclosed and which comprises a fluid enclosure having a movable piston means mounted therein which sealably divides the enclosure into a pumping chamber on one side and an actuating chamber on the other side. The piston means may comprise either a slideable piston or a flexible diaphragm. An inlet valve and a separate outlet valve are each connected to the pumping chamber, and a control system is provided for intermittently supplying a pressurized working fluid to the actuating chamber so as to intermittently move the piston means in the discharge direction, with the piston means being moved in the opposite or suction direction by either the pressure of the fluid being conveyed, or a suitable spring. The control system for advancing the piston means in the discharge direction includes a source of pressurized working fluid, a working fluid line extending between the source and the actuating member, and a valve operatively connected to the working fluid line for intermittently opening the line to a discharge tank or the like to release the pressure therein.