SUN HYDRAULICS
RDDAKDV

***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 RDDAKDV (RDDAKDV) is a direct-acting relief cartridge valve designed to protect hydraulic systems from pressure transients by limiting pressure rise through throttling flow. This normally closed, pressure-limiting valve opens to tank port 2 when the inlet port 1 pressure reaches the setpoint, ensuring smooth operation with minimal leakage and high dirt tolerance. It features interchangeable physical and functional properties across all two-port relief cartridges, except pilot reliefs, with consistent flow paths and cavity sizes for a given frame size. The valve can handle maximum pressure at port 2, making it suitable for cross-port relief circuits and load-holding applications. Adjustment of the valve requires system pressure removal due to seal exposure on the adjust screw. The RDDAKDV is relatively insensitive to oil temperature variations and contamination, ensuring maximum repeatability when selecting a spring range close to mid-range or higher between minimum and maximum pressures. The backpressure on tank port 2 directly affects the valve setting at a 1:1 ratio. Cartridges with EPDM seals are compatible with phosphate ester fluids but may be damaged by petroleum-based substances. Its floating style construction minimizes internal part binding risks due to installation torque or machining variations in cavity/cartridge configurations. Key specifications include a T-10A cavity, Series 1 capacity of 25 gpm (95 L/min), maximum operating pressure of 5000 psi (350 bar), typical response time of 2 ms, and maximum valve leakage at reseat of 10 drops/minute (0.7 cc/min). The reseat value is approximately 90% of the setting, with adjustment achieved through six clockwise turns to increase settings. The valve's hex size measures 7/8 inch (22.2 mm) with an installation torque range of 30-35 lbf ft (41-47 Nm).