摘要 |
The present hydraulic system for driving a submersible pumping unit has an above-ground pump for pumping oil through a hydraulic motor in the submersible pumping unit, and a check valve between the above-ground pump and that hydraulic motor to prevent the reverse flow of oil after the submersible pumping unit is turned off. A pressure regulating valve limits the oil pressure to the hydraulic motor. The inlet flow to the above-ground pump is filtered.
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