To prevent the leakage of a product through a vent hole by providing a sealing means for preventing the entering of a liquid to a vessel through the vent hole and engaged liquid-tightly and slidably with a piston system to seal at the time of using a pump under a moisture atmosphere by closely sealing the gas vent hole in suction and exhaust operation.
The vessel vent hole 19 is closely sealed till the end period or near the end period of a pressurizing process in suction and exhaust operation. Further a vent passage for transporting only air to the vessel 12 is shut off from infiltrating or entering a small quantity of the liquid into the inside of the vessel 12 through a water inlet 57 in the moisture environment at the time of suction and exhaust operation by the sealing device 49 engaged liquid- tightly and slidably with the piston system 26 to seal just like at the time of weighing and distributing a hair shampoo or a hair conditioner for shower. As a result, the leakage of product through the vent hole 19 caused by the pressurized state of the vessel 12 as when a plunger is a fixed position in transportation and storage is prevented.
LI TANNY
SIEGEL KENNETH D
