SUN HYDRAULICS
RDHAQSN

***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 RDHAQSN (RDHAQSN) is a direct-acting relief cartridge designed to protect hydraulic components from pressure transients by limiting pressure rise. This normally closed, pressure-limiting valve opens to the tank port when the inlet port reaches the valve setting, ensuring smooth and quiet operation with minimal leakage and high dirt tolerance. It features a 2-port design that is interchangeable with other relief cartridges of the same frame size and flow path. The valve can handle maximum pressure at port 2, making it suitable for cross-port relief circuits and load holding applications. Adjustments require removing system pressure due to seal exposure on the adjust screw. It is designed for insensitivity to varying oil temperatures and contamination, with optimal performance achieved by selecting a spring range where the desired setting falls midrange or higher. The design includes Sun's floating style construction to prevent internal part binding due to installation torque or machining variations. Its cavity size is T-16A, Series 3, with a capacity of 100 gpm (380 L/min) and maximum operating pressure of 5000 psi (350 bar). The typical response time is 2 ms, with maximum valve leakage at reseat being 10 drops/min (0.7 cc/min) and reseat at 90% of setting. Adjustment requires six clockwise turns for increased settings, utilizing an internal hex size of 5/32 in (4 mm). The valve has a hex size of 1-1/4 in (31.8 mm), installation torque of 150-160 lbf ft (203-217 Nm), locknut hex size of 9/16 in (15 mm), locknut torque of 80-90 lbf in (9-10 Nm), weighs approximately 1.30 lb (0.60 kg), and includes a Viton seal kit option under part number 990316006.