Direct-Acting and Indirect-Acting Pumps:

A few reciprocating pumps are powered through prime movers which also have reciprocating motion, like as a reciprocating pump powered through a reciprocating steam piston. A piston rod of the steam piston might be directly linked to the liquid piston of the pump or it might be indirectly linked along with a beam or linkage. It has a plunger on the liquid (pump) end which is directly driven through the pump rod (also the piston rod or extension thereof) and carries the piston of the power end. Indirect-acting pumps are driven through means of a beam or linkage linked to and actuated through the power piston rod of a separate reciprocating engine.