The counterbalance valve and brake valve have similar symbols (Fig. 3.26). The single difference is that the brake valve has a remote pilot line in addition to an upstream pilot line. As with the sequence and pressure-reducing valves, a check valve is built in to allow free flow in the reverse direction.
A couple of definitions are required before continuing our discussion of counterbalance and brake valves.
Resistive load: A load that acts in the opposite direction to actuator motion.
Overrunning load: A load that acts in the same direction as actuator motion.