How a trigger spray bottle pumps liquid upward
A trigger spray bottle uses a small pump and one-way valves. Squeezing the trigger reduces the pump chamber's volume and forces liquid towards the nozzle; releasing it lets the chamber refill through the tube. Repeated squeezes move liquid upward without keeping the whole bottle under high pressure.
Go deeper
Two strokes and one-way flow
Inside a typical trigger sprayer, the trigger moves a small piston. Squeezing it reduces the volume of a chamber, raising pressure and driving liquid towards the nozzle through an outlet valve.
A spring returns the piston when the trigger is released. The expanding chamber draws liquid up the dip tube through an inlet valve. The valves prevent the liquid from simply moving back and forth along the same route.
Each trigger cycle supplies the pumping energy. The bottle is not relying on a stored propellant as an aerosol can does.
- Squeeze: liquid is pushed towards the outlet.
- Release: the chamber refills from the bottle.
A new or empty sprayer may need several squeezes to replace air in the pump with liquid. Many nozzles can change the output between a fine spray and a more concentrated stream.