SUN HYDRAULICS
RELIEF CART
RDBALWN

***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 RDBALWN (RDBALWN) is a direct-acting relief cartridge designed to protect hydraulic components from pressure transients by limiting pressure rise when the inlet port reaches the valve setting. This normally closed, pressure-limiting valve opens to tank port 2, throttling flow smoothly and quietly with essentially zero leakage. It is dirt tolerant, immune to silting, and responds rapidly with a typical response time of 2 milliseconds. The RDBALWN is physically and functionally interchangeable with other 2-port relief cartridges except for pilot reliefs, featuring the same flow path and cavity for a given frame size. It can accept maximum pressure at port 2, making it suitable for cross-port relief circuits and load-holding applications. The valve's construction minimizes the potential for internal parts binding due to excessive torque or machining variations. To ensure repeatability, select a spring range where the desired setting is mid-to-high between minimum and maximum pressures. Note that backpressure on tank port 2 adds directly to the valve setting at a 1:1 ratio. The adjustment process requires removing system pressure before making changes due to exposure of seals on the adjust screw to system pressure. Cartridges configured with EPDM seals are compatible with phosphate ester fluids but are unsuitable for petroleum-based fluids. With a capacity of 12 gpm (45 L/min), this cartridge operates at a maximum pressure of 5000 psi (350 bar), featuring factory settings established at 4 gpm (15 L/min) and reseating at 85% of the setting. The valve's compact design includes specific installation torques and hex sizes for both the adjustment screw and locknut, ensuring secure adjustments within specified tolerances.