Research and application of hydraulic feedback and self-sealing efficient plunger pump

In view of the problem of high friction, high leakage and short life existing in conventional plunger pumps, this articlepresents a new hydraulic feedback and self-sealing plunger pump (HSP). Plunger core of this pump is made of metal tube with severalradial holes in the middle. There is an elastic expansion sleeve on the middle screen plunger core; several wear resistance seal rings are onthe expansion sleeve. In the upstroke, fluid pressure in the plunger acts on inner surface of expansion sleeve and makes it expand outward,keeping the seal ring press on the inner wall of pump barrel to form good sealing. In the down stroke, expansion sleeve recover and thereappears a clearance between plunger and pump barrel. Laboratory test shows that the pump has realized the designation of friction freedown stroke, self-sealing with no leakage upstroke, and long life with wear resistance seal ring. Field tests indicate that in the condition ofadequate fluid supply, pump efficiency reached 60%~80%, moreover the pump has been working efficiently for two years.