Application: Double-acting cylinders. Provides positive holding and controlled, “chatter-free†lowering of a load.
Operation: Load is raised at flow rate of pump, and held when pump is shut off. When the pump is shifted to “retract,†the counter balance valve will continue to hold the load until system pressure exceeds pressure caused by load. The load can then be lowered smoothly to the flow rate of the pump. The counter balance valve is designed to operate with pumps having a high pressure flow rate of up to 120 cu. in./min. and cylinder ratios of 3 to 1.
CAUTION: The 9720 patented counter balance valve has a pilot pressure as high as 3,000 psi. Because this pressure is applied to the rod end of the cylinder while it is already under load, the system should not be sized for loads greater than 80% of cylinder rated capacity.
CAUTION: To prevent sudden, uncontrolled descent of a load as it is being lowered, use a Load Lowering Valve (No. 9596) or Counter Balance Valve (No. 9720) in conjunction with the directional valve used in your application.
| Order No. | Cylinder Application * |
Operation | Valve Type | Volt | Advance / Return | Advance / Hold Return | Posi-Check® Feature | Weight (lbs.) |
|---|---|---|---|---|---|---|---|---|
| 9720 | S.A. & D.A. | Automatic | Counter Balance Valve | — | Special | — | — | 10.0 |
| 9721 | S.A. & D.A. | Automatic | Counter Balance Valve | — | Special | — | — | 9.2 |
| * “S.A.†represents single-acting cylinders, “D.A.†represents double-acting cylinders | ||||||||
| Catalog | |
| Operating Instructions | |
| Parts List | |
