SUN HYDRAULICS
RDDALWV

***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 RDDALWV (RDDALWV) is a direct-acting relief cartridge valve designed to protect hydraulic components from pressure transients. This normally closed, pressure-limiting valve opens to tank port 2 when inlet port 1 reaches the set pressure, throttling flow to limit pressure rise. It features smooth, quiet operation and is highly dirt-tolerant, with essentially zero leakage and immunity to silting. The valve's design allows for fast response times and is suitable for use in cross-port relief circuits as it can accept maximum pressure at port 2. The adjustment screw's seals are exposed to system pressure, necessitating removal of pressure before adjustments can be made. It is recommended that users select a spring range where the desired relief setting falls between midrange to high for maximum repeatability. The valve is relatively insensitive to variations in oil temperature and contamination, making it ideal for load-holding applications. Additionally, back pressure on the tank port directly adds to the valve setting at a 1:1 ratio. The RDDALWV incorporates Sun's floating style construction which minimizes binding risks due to installation or machining variations. It fits into cavity T-10A and has a series 1 capacity of up to 25 gpm (95 L/min). The factory pressure settings are established at 4 gpm (15 L/min) with a maximum operating pressure of 5000 psi (350 bar). Typical response time is approximately 2 ms with maximum leakage at reseat being only 10 drops/min (0.7 cc/min), and reseat occurring at 90% of the setting. The valve requires specific torques for installation and adjustment operations and weighs approximately .30 lb (.15 kg). For systems using phosphate ester fluids, cartridges configured with EPDM seals should be used as exposure to petroleum-based substances could damage these seals.