SUN Holding Valves - Smooth, chatter-free cylinder control. Locking counterbalance valves are usually mounted directly to a cylinder to lock it in position when the directional valve is in neutral. Counterbalance valve provides smooth, positive motion control of a cylinder with a high load-generated pressure tending to cavitate it, such as on booms, cranes or outriggers, or on overcenter applications. Used on booms and manlifts to protect against damaged hoses - valve will not allow cylinder to move until there is positive pressure to the opposite port. Single valves for cylinders loaded in only one direction. Dual valves lock cylinder in both directions, and for overcenter applications. Standard pilot ratio 3:1. Aluminum body, steel valve cartridge. Internal relief to prevent overpressure. Set relief 1.3 times load-induced pressure minimum (usually left at factory setting of 3000 PSI). Turn adjustment screw CW to decrease setting, all the way in to release load manually.
Not for use in systems below 750 PSI