Sun Hydraulics has established a strong foundation for consistently delivering exceptional performance in all aspects of their business. From product design and service delivery, Sun Hydraulics stands out in the industry.

Since the beginning, Sun products have been setting the standard for the screw-in hydraulic cartridge valve industry. Sun's floating cartridge construction and cavity design approach allows products to operate precisely and reliably at higher pressures and flow rates in the most demanding applications. The generous porting area, coupled with our manifold design and construction techniques, result in integrated packages that can be up to 50% smaller than competitive offerings.

Sun cartridge valves are offered in five primary sizes, with flow capacity and controlled horsepower doubling with each successive size. Within each broad functional area (pressure, flow, load control, etc.), multiple variations are available to help you optimize your control circuit, from individual valves to complete integrated packages. Their expansive product line allows you to develop the best control solution for your hydraulic application.

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 200 psi (14 bar).
• All 4-port counterbalance, load control, and pilot-to-open check cartridges are physically interchangeable (i.e. same flow path, same cavity for a given frame size).
• 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.
• Pressure at port 4 is added to the effective relief setting at a rate of 1 plus the pilot ratio times the pressure.
• Sun counterbalance cartridges can be installed directly into a cavity machined in an actuator housing for added protection and improved stiffness in the circuit.
• This valve has positive seals between all ports.
• With vented valves, a lower pilot ratio may be required to achieve machine stability compared to non-vented valves.
• Incorporates the Sun floating style construction to minimize the possibility of internal parts binding due to excessive installation torque and/or cavity/cartridge machining variations.

Technical Specification

Control - Standard Screw Adjustment
Functional Setting Range - 70-280 Bar / 1000-4000 PSI, 210 Bar / 3000 PSI Standard Setting
Seal Material - Buna-N