oscillating displacement pump meaning in English

摆动泵
摆动式排量泵
往复泵

Oscillating displacement pump which may achieve a considerably longer trouble - free operation than a conventional diaphragm piston pump
往复式容积泵，有比传统隔膜活塞泵长的多的无故障运行时间。
The hose diaphragm piston pumps are hermetically sealed , leakproof , oscillating displacement pumps with a unique technical and economical value
软管隔膜活塞泵是严密密封、无泄露往复式容积泵，具有独一无二的技术和经济价值。