| 摘要 |
<p>An improved, unattended, liquid pumping device (10) for oil and gas wells featuring a bellows (35) controlled flow valve (20) that opens and closes at preset pressures. Additionally a well head receiver (60) design that releases shut in production gas below the pumping device (10) and provides a positive pressure differential across the pumping device (10) prior to valve (20) opening.</p> |
