Sun Hydraulics CB** Counterbalance Valves - Three Port

Three port counterbalance cartridges (with pilot-to-open assist) are modulating devices that allow free flow from port 2 (inlet) to port 1 (load) and then block reverse flow until a pilot pressure inversely proportional to the load pressure is applied at port 3 (pilot). The modulation of a counterbalance valve is a function of both the load pressure and the pilot pressure, yielding an “inverse pilot ratio”; light loads require more pilot pressure and heavy loads less pilot pressure to open the counterbalance valve, helping to improve stability and providing fine motion control.