Double acting hydraulic rams

Double acting rams can exert force in two directions. Under the influence of hydraulic pressure the piston rod of a double acting ram will both extend and retract. The diagram shows a typical double acting ram. Pumping fluid under pressure into port A (full bore ) will extend the piston rod, the force exerted will be dependant on the cylinder bore diameter and the fluid pressure. Pumping fluid into port B ( annulus ) will cause the piston rod to retract, the force exerted is dependant on the cylinder bore diameter, the piston rod dia, and the fluid pressure.