Abstract: This invention provides a double-acting, double diaphragm pump particularly for fluids such as chemical compounds. The pump employs adjustable disk members mounted on a reciprocable rod connecting and actuating the diaphragms. These disks alternately engage the extending shaft of a pilot valve to move the valve and redirect the flow of pressurized fluid therethrough. The pressurized fluid behind the diaphragm is now caused to flow to a slide valve and cause it to be moved to an opposite limit. The slide valve is cycled by the pilot valves as the disks on the reciprocated rod engage the pilot valves. Each pump half has the exterior wall member disposed to carry two one-way valves, one valve to inhibit inward flow to the chamber and one valve to inhibit flow from the chamber.

Abstract: This present invention pertains to a flap valve particularly used with and in chemical pumps. This valve is spring-biased to and toward a port formed in a wall of the pump. The valve includes a laminate structure at the hinge area which provides alternate Teflon and corrosion resistant, bright sheet stainless steel riveted together with front and back facing portions also of Telfon. The laminated portion has extending portions of each laminate member and in each of these portions are formed elongated apertures that are aligned to provide vertically elongated slotted holes sized to slide on the shanks of studs mounted in the wall of the pump. The extending portion of the laminate is mounted with front and back spacer members so that the laminate portion is spaced from the wall about the extent of the front facing portion.