SUN HYDRAULICS
RQCBKNN

***Disclaimer: The following summary contains information gathered from various sources such as product descriptions, technical specifications and catalogs. While efforts have been made to provide accurate details, inaccuracies may occur. It is advised to verify all information by contacting Sun Hydraulics directly.***
The Sun Hydraulics RQCBKNN (RQCBKNN) is a kickdown relief cartridge designed to function similarly to a circuit breaker in hydraulic systems. This valve kicks completely open and remains open once the pressure at inlet port 1 exceeds the set point, allowing unrestricted flow from port 1 to tank port 2. It stays open as long as the pressure at port 1 is greater than that at port 2, and resets only when flow ceases and pressures equalize. Protected by a 150-micron stainless steel screen, this valve is not suitable for load holding applications and is best used on the actuator side of a system. If applied on the pump side, pump flow must be stopped for reset. The back pressure on tank port 2 directly adds to the valve setting at a 1:1 ratio. All two-port relief cartridges are interchangeable within their frame size, featuring Sun's floating style construction to reduce internal part binding risks due to excessive torque or machining variations. The RQCBKNN has a capacity of 12 gpm (45 L/min), with maximum operating pressure up to 5000 psi (350 bar) and typical response time of 25 ms. Maximum leakage at specified conditions is minimal, ensuring efficient operation. Installation specifications include a valve hex size of 3/4 inch (19.1 mm) and installation torque between 20-25 lbf ft (27-33 Nm). The adjustment screw has an internal hex size of 5/32 inch (4 mm), while the locknut requires a torque of 80-90 lbf in (9-10 Nm). This cartridge weighs approximately .20 lb (.10 kg) and can be sealed with Viton seal kits for optimal performance in various applications such as portable grain augers where safety mechanisms are crucial.