It is the key study how to make sure the pressure distribution of liquid in the pump barrel and to study the pump valve-ball's movement to improve the systematic efficiency.

对有杆抽油泵泵阀运动规律的研究和确定抽油泵泵阀筒内液体压力的分布是提高抽油机井系统效率研究的关键性课题。

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The pump barrel of the hand-press pump is arranged in a liquid medicine box, and the pressure storage barrel is usually arranged at the outer side of the liquid medicine box.

手压泵的泵筒设置在药液箱里，手压泵的储压筒一般设置在药液箱外。

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Light, sweet crudes are cheaper to pump, transport, and distill and produce more gasoline per barrel than other types of crudes so it generally goes for more dollars per barrel than others.

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Sweet light crude oil yields the most gallons of gasoline per barrel of oil and since it has low viscosity and low density, it is comparatively inexpensive to pump, transport, and refine.

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