Abstract: A discharge valve system is provided for a finger-operable pump with an actuating plunger. In one embodiment, the plunger includes a piston disposed in a pump pressurizing chamber. In another embodiment, the plunger is slidably disposed on a fixed piston so that the plunger and piston together define a pressurizing chamber. In either embodiment, the chamber receives fluid from a container. The actuating plunger defines a discharge passage establishing communication between the ambient atmosphere and the chamber. The discharge valve system includes a valve seat defined by the plunger in the discharge passage.