SUN HYDRAULICS
RDJALEN

***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 RDJALEN (RDJALEN) is a direct-acting relief cartridge designed to protect hydraulic components from pressure transients. This normally closed, pressure-limiting valve operates by opening to tank port 2 when the inlet port 1 pressure reaches the set threshold, effectively throttling flow to control pressure rise. Notable for its smooth and quiet operation, this valve is essentially zero-leak, dirt-tolerant, immune to silting, and exhibits rapid response times. It features a floating style construction that minimizes internal binding risks due to installation torque or machining variations. The RDJALEN model is suitable for cross-port relief circuits as it can handle maximum pressure at port 2. Its design allows for adjustment only when system pressure is removed; the process includes checking the setting, removing pressure, adjusting the valve, and rechecking the setting. The valve maintains stability across varying oil temperatures and contamination levels. For optimal performance and repeatability, selecting a spring range where the desired relief setting is mid-to-high between minimum and maximum pressures is recommended. This cartridge supports load-holding applications and accounts for backpressure on tank port 2 with a direct additive effect on valve settings at a 1:1 ratio. Cartridges with EPDM seals are compatible with phosphate ester fluids but are susceptible to damage from petroleum-based substances. The RDJALEN fits into cavity T-18A Series 4 with a capacity of up to 200 gpm (760 L/min), operates at a maximum of 5000 psi (350 bar), and typically responds within 2 milliseconds. Factory settings are established at 4 gpm (15 L/min), with leakage rates at reseat not exceeding 10 drops per minute (0.7 cc/min).