There are duties, such as cleaning of grinding machine coolant tank, tank of machines such as CNC lathes, where liquid is full of emery, metal turnings and abrasives.

Diaphragm Hand Pump does this job easily, as it simply sucks and pushes out abrasive liquid without churning/clogging. 

Low cost Cast Iron pumps (1” or 1.5) with Nitrile (Buna-N) rubber parts are used for this application.