Abstract: The pump is formed by a body having a cavity with a piston chamber in which a piston is reciprocated. A rotatable crank shaft is provided to reciprocate the piston along inward and outward strokes to draw ammonia into the pump by way of an inlet and then to pump the ammonia out by way of an outlet. A diaphragm in a diaphragm chamber is provided to separate the ammonia from the piston and piston chamber. One side of the diaphragm is in fluid communication with the piston chamber and the other side is in fluid communication with the inlet and outlet. A liquid is provided for flow into and out of the piston chamber to cause the diaphragm to move inward and outward to cause the suction and pumping action for the ammonia as the piston reciprocates in its inward and outward strokes.

Abstract: The pump is formed by a body having a cavity with a cylindrical chamber in which a piston is reciprocated toward and away from an inlet and outlet aperture. A crank shaft extends through an aperture formed through the piston transverse to its axis and through opposite walls of the cavity. The crank shaft has a cam located in the piston aperture. Upon rotation of the crank shaft, the cam alternately engages opposite facing cam surfaces of the piston in the piston aperture to reciprocate the piston to draw fluid into the chamber from an inlet path and then to pump the fluid out through an outlet path. The piston has spaced apart O-rings on its outer wall which engage the chamber wall upon reciprocation of the piston.