| 摘要 |
Downhole pumps for producing hydrocarbons and/or other fluids from a well bore include a barrel having a plunger or plunger valve disposed therein and a stationary valve engaged with the barrel. The valve(s) include(s) an outer housing and an inner piston movable within the outer housing. Responsive to movement of the plunger or plunger valve relative to the barrel, the inner piston(s) is(are) movable between a first position that permits fluid flow through the valve and a second position that prevents fluid flow therethrough. |
