Abstract: A check valve cartridge for a fluid pump, the check valve cartridge including: a valve seat; a flap valve member seated on the valve seat, the flap member having a first portion movable toward and away from the valve seat; a bumper seated on the flap member, said bumper member for biasing the first portion of the flap valve member toward the valve seat. The check valve cartridge also including a stop member located on the bumper, between the stop member and the flap member; and fastening means for joining the base, flap member, bumper, and stop member to form the integral valve cartridge. The check valve cartridge is seated in a recess formed in the pump housing and is located between the pump housing and a flow manifold.