短语词组短語valve plate type piston pump 閥板式活塞泵;牐板式活塞泵valve box type piston pump 閥室式活塞泵;閥箱式活塞泵valve pot type piston pump 閥室式活塞泵;閥箱式活塞泵valve type piston pump coupling 閥形活塞泵聯軸器 返回 valve type piston pump