Abstract: A diaphragm pump is provided having a plurality of piston inlets connecting a hydraulic fluid source with the piston chamber and a plurality of check valves each having a ball and valve seat disposed within the inlets. The valve seat includes a conical section sloped such that the tangential contact point between the ball and valve seat is located at a position outward from the inner edge of the valve seat. The distance the ball is permitted to move between the open and closed positions is such that the check valve closes substantially in conjunction with the piston beginning its power stroke and the ball is not able to generate a high closure velocity. A diaphragm plunger includes a spherical surface portion designed to impact a diaphragm stop at a position away from the edges of the stop and plunger. An isolation reservoir is connected to a piston reciprocating chamber such that hydraulic fluid completely fills the piston reciprocating chamber and further flows into the isolation reservoir.

Abstract: A spray gun includes a barrel portion and a handle portion having a control lever pivotally mounted to a lower end of the handle controlling a valve system. The spray gun includes an interchangeable fitting for receiving two fluid lines. The lever is movable between a first lockable spray position, opening the valve system to spray one fluid, and a second spray position spraying two fluids.