变容真空泵 meaning in English

positive displacement pump

Petroleum , petrochemical and natural gas industries - reciprocating positive displacement pumps
石油石化和天然气工业.往复式变容真空泵
Petroleum , petrochemical and natural gas industries - reciprocating positive displacement pumps
石油石油化学和天然气工业.往复式变容真空泵
Reciprocating positive displacement pumps and pump units - technical requirements iso 16330 : 2003 ; german version en iso 16330 : 2003
往复运动变容真空泵和泵装置.技术要求
Petroleum , petrochemical and natural gas industries - reciprocating positive displacement pumps iso 13710 : 2004 ; english version en iso 13710 : 2004
石油石油化学和天然气工业.往复式变容真空泵