A venting system of a manually operated trigger sprayer vents the interior of a liquid container connected to the trigger sprayer. The trigger sprayer is provided with a vent chamber that surrounds the pump chamber, and a vent piston that surrounds the pump piston. The vent piston is received in the vent chamber for reciprocating movements between a vent closed and vent opened position in the vent chamber, and the vent chamber having two different interior diameter sections with a larger interior diameter section reducing drag on the vent piston when the vent piston is moved to the vent opened position.
This patent application is a continuation-in-part of patent application Ser. No. 10/961,286, which was filed on Oct. 8, 2004, and is currently pending.