How does the hand sanitizer pump head work

We often see hand sanitizer in such a bottle, press the pump head on the top of the bottle, and the hand sanitizer will flow out of the infusion tube.
The working principle of the hand sanitizer pump head is the same as that of the piston pump. It also uses the movement of the piston and the opening of the single-phase valve to close the air in the discharged liquid removal cylinder, causing strong friction between the internal and external pressure, so that the liquid is under the action of atmospheric pressure. Rising up, draining the hand sanitizer bottle from the drain tube has a push-type suction
It is mainly composed of a catheter, a radial leaf ball valve, a yellow elastic tube, a hollow plunger, a piston, a liquid outlet pipe, and a barrel-removing liquid. When the hand presses down the liquid, the pressure in the liquid removal barrel is too large, and the spring valve is closed by the compressed leaf stem valve. At the same time, due to the downward movement of the piston, the liquid outlet hole on the hollow plunger is opened at this time, and the liquid in the liquid removal hole is opened. It flows out of the pipe from the liquid removal hole. When the hand is released, the yellow spring returns, which reduces the pressure in the liquid removal tank on the piston, the liquid removal hole on the hollow plunger is closed, the leaf stem valve is opened under the action of atmospheric pressure, and the liquid flows from the guide. The liquid pipe enters the liquid removal barrel through the leaf stem valve, and under the action of atmospheric pressure, the liquid pipe enters the liquid removal barrel through the liquid pipe. In this way, the piston reciprocates up and down in the barrel, continuously sucking the liquid out of the bottle.