SUN HYDRAULICS
RELIEF CART
RDFALAN

***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 RDFALAN (RDFALAN) is a direct-acting relief cartridge valve designed to safeguard hydraulic components from pressure transients by limiting pressure rise when the inlet port pressure reaches the valve setting. This normally closed, pressure-limiting valve smoothly and quietly opens to tank port 2, providing essentially zero leakage and high dirt tolerance. It is immune to silting and offers rapid response times, making it suitable for load-holding applications and cross-port relief circuits. The RDFALAN can handle a maximum operating pressure of 5000 psi (350 bar) and has a capacity of 50 gpm (200 L/min). The adjustment process requires removing system pressure before changing settings, as seals on the adjust screw are exposed to system pressures. The valve is relatively insensitive to changes in oil temperature and contamination, ensuring consistent performance across varying conditions. It incorporates Sun's floating style construction, minimizing internal part binding due to installation torque or machining variations. For optimal performance, select a spring range where the desired relief setting is midrange to high between minimum and maximum pressures. The cartridge can accept maximum pressure at port 2, with backpressure on this port directly additive to the valve setting at a 1:1 ratio. Cartridges configured with EPDM seals are intended for phosphate ester fluid systems; exposure to petroleum-based fluids will damage these seals. Installation requires specific torques for both the valve body (45-50 lbf ft) and locknut (80-90 lbf in), with adjustments made using an internal hex size of 5/32 inches. The RDFALAN has a factory pressure setting established at 4 gpm (15 L/min), typical response time of 2 ms, and reseats at 90% of its set value with minimal leakage upon reseat.