Sun Hydraulics 9LQ4 Hydraulic Counterbalance Valve Assembly

Sun Hydraulics 9LQ4 Hydraulic Counterbalance Valve Assembly is a three-port, line-mounted counterbalance valve designed to hold a load in hydraulic circuits and enable controlled lowering by pilot pressure. As part of Sun’s counterbalance family, it is used across mobile and industrial systems to prevent overrunning cylinders and maintain stable loads in booms, lifts, and other actuated equipment. In operation, the valve remains closed until the pilot pressure surpasses the preset setting, allowing flow from the pressure port to the actuator while the load is held in check at the cylinder. This configuration matches Sun’s typical three-port line-mounted counterbalance assemblies, which use P, A, and T ports in a compact package. The Sun literature notes that counterbalance valves offer adjustable set pressures and pilot-pressure ratios, with common pilot ratios cited such as 2.3:1, 4.5:1, and 10:1 for select configurations. For exact specifications, including port sizes, setting range, and actuation options for part 9LQ4, consult Sun Hydraulics catalogs and distributor datasheets for the precise model tag CBIA/LIV/HBB 9LQ4, and related CBCA family references.