Piston pump piston reciprocating motion, make the pump cavity working volume cycles, suction and discharge the liquid.From the pump cylinder, piston, in and out of the water valve, in and out of the water pipe, connecting rod and gear.Driven by power piston in the pump cylinder for reciprocating motion.Parker PV140R1K1T1NMMC is a standard constant pressure variable pump control, origin Germany, weight 90KG, reliable quality.When the piston upward movement, inlet valve open, the water entering the pump cylinder, at the same time water closed the valve on the piston, piston top water varies with the piston upward; When the piston moves downward, fill valve closed, open valve on the piston, at the same time make the pump cylinder inferior vena water pressure into the cavity, and moving up to the outlet pipe, and so repeatedly into the water and ascension, make water discharge from the outlet pipe.