… Pumps for liquids, whether or not fitted with a measuring device; liquid elevators. …
Explanatory notes
… includes : (1) Diaphragm pumps . These incorporate a vibrating membrane of metal, leather, etc. (actuated either … “Oil-cushion” pumps (for drainage, irrigation, pumping viscous liquids, acids, etc.). In these, a fluid immiscible … according to the nature of the rotating mechanism, viz. : (1) Gear pumps . The liquid is displaced by the …