A manually operated sprayer for a container of liquid to be sprayed includes variable volume pump means having liquid inlet and outlet means for discharging the contents of the container. The sprayer further includes a control module having product and vent valves reciprocably disposed therein, the product and vent valves being simultaneously reciprocable by means of the manual actuator between valve open and valve closed positions. In the valve open position, the product and vent valves respectively prevent flow of product and air respectively into the liquid inlet means and into a vent passage in communication between atmosphere and an interior of the container, and in the vent closed position, the product and vent valves respectively enable flow of product and air respectively into the liquid inlet means and into the vent passage.