A pump apparatus is provided which comprises a plurality of displacement pumps each connected to a check valve apparatus. The displacement pumps each comprises a reciprocating piston within a housing having an interior wall spaced apart from the piston. The check valve apparatus comprises two check valves that control fluid flow under pressure exerted by the reciprocating piston from a fluid reservoir to a point of use of the fluid. Pistons of the displacement pumps are driven by a common motor.