SUN HYDRAULICS
RDDALSE

***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 RDDALSE (RDDALSE) is a direct-acting relief cartridge designed to safeguard hydraulic components against pressure transients. These normally closed, pressure-limiting valves open to the tank port when inlet pressure reaches the set threshold, effectively throttling flow to control pressure rise. Notable for their smooth and quiet operation, these valves are essentially zero-leak and dirt-tolerant, making them immune to silting and ensuring rapid response times. The RDDALSE model is functionally interchangeable with other 2-port relief cartridges of the same frame size, making it versatile in various applications including cross port relief circuits and load holding scenarios. The valve's design allows it to handle maximum pressure at port 2, with backpressure on this port being directly additive to the valve setting at a 1:1 ratio. It features a floating style construction which reduces the risk of internal component binding due to excessive installation torque or machining variations. The valve is relatively insensitive to changes in oil temperature and contamination levels, ensuring consistent performance across different conditions. For optimal repeatability, it is recommended to select a spring range where the desired relief setting falls within the mid-to-high range of its minimum and maximum pressure capabilities. The RDDALSE model incorporates EPDM seals for compatibility with phosphate ester fluids; however, exposure to petroleum-based fluids will damage these seals. This cartridge has a capacity of 25 gpm (95 L/min) and operates at a maximum pressure of 5000 psi (350 bar), with typical response times around 2 ms. It features an adjustment screw that requires system pressure removal before adjustments can be made. With its robust construction and reliable performance characteristics, the RDDALSE is well-suited for demanding hydraulic applications requiring precise overpressure protection.