The inside surface of the pump barrel adopts hard chromium plated ,the outside of plunger adopts spraying welding nickel-based alloy,the key parts, such as the valve bonnet and the base, all adopt the strong corrosion resisting property and the perfect mechanical property material . The pumps of this series possess excellent wear-resisting property,its service life is 1-3 times longer than ordinary ones. Due to its preeminent corrosion resistance property, it can be used in the medium with H2S,CO2 of corrosive salt water.