SUN HYDRAULICS 3:1 pilot ratio, semi-restrictive counterbalance valve (CBBCLHN)

Counterbalance valves with pilot assist are meant to control an overrunning load. The check valve allows free flow from the directional valve (port 2) to the load (port 1) while a direct-acting, pilot-assisted relief valve controls flow from port 1 to port 2. Pilot assist at port 3 lowers the effective setting of the relief valve at a rate determined by the pilot ratio.

Other names for this valve include motion control valve and over-center valve.

• Counterbalance valves should be set at least 1.3 times the maximum load induced pressure.
• Turn adjustment clockwise to decrease setting and release load.
• Full clockwise setting is less than 200 psi (14 bar).
• Backpressure at port 2 adds to the effective relief setting at a ratio of 1 plus the pilot ratio times the backpressure.
• Reseat exceeds 85% of set pressure when the valve is standard set. Settings lower than the standard set pressure may result in lower reseat percentages.