SUN HYDRAULICS
RDFACSN

***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 RDFACSN (RDFACSN) is a direct-acting relief cartridge valve designed to protect hydraulic components from pressure transients by limiting pressure rise. This normally closed, pressure-limiting valve opens when the inlet port pressure reaches the set threshold, allowing flow to the tank port and ensuring smooth, quiet operation with minimal leakage. It is dirt tolerant and resistant to silting, making it highly reliable and fast-responding. The RDFACSN is interchangeable with other 2-port relief cartridges of the same frame size and flow path, accepting maximum pressure at port 2 for cross-port relief circuits. The valve's adjustment requires system pressure removal due to exposed seals on the adjust screw. This model is suitable for load-holding applications and remains stable despite varying oil temperatures or contamination. For optimal performance, select a spring range where the desired setting falls in the mid-to-high range between minimum and maximum pressures. The back pressure on tank port 2 directly adds to the valve setting at a 1:1 ratio. Cartridges with EPDM seals are intended for phosphate ester fluid systems; exposure to petroleum-based fluids will damage these seals. Featuring Sun's floating style construction, this valve minimizes internal part binding risks due to excessive installation torque or machining variations. It fits into a T-3A cavity of Series 2 with a capacity of up to 50 gpm (200 L/min) and operates under pressures up to 5000 psi (350 bar). The typical response time is approximately 2 ms, with maximum leakage at reseat being 10 drops/min (0.7 cc/min). Adjustments can be made using an internal hex screw with specific torque requirements for both installation and locknut adjustments. This robust cartridge weighs approximately .50 lb (0.25 kg) and can be serviced using Viton seal kits as needed.