SUN HYDRAULICS
RDHALEN

***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 RDHALEN (RDHALEN) is a direct-acting relief cartridge designed to protect hydraulic components from pressure transients by limiting pressure rise when the inlet port pressure reaches the valve setting. This normally closed, pressure-limiting valve opens to the tank port, throttling flow smoothly and quietly with minimal leakage. The RDHALEN is dirt tolerant, immune to silting, and responds quickly with a typical response time of 2 milliseconds. It features interchangeable functionality across 2-port relief cartridges for a given frame size and can handle maximum pressures at port 2, making it suitable for cross-port relief circuits and load-holding applications. The valve's design incorporates Sun's floating style construction to prevent internal parts from binding due to excessive installation torque or machining variations. It is relatively insensitive to oil temperature variations and contamination, ensuring consistent performance. The seals on the adjustment screw are exposed to system pressure, requiring adjustments only when the system is depressurized. For optimal repeatability, select a spring range where the desired relief setting falls in the mid-to-high range of its capacity. The RDHALEN has a maximum operating pressure of 5000 psi (350 bar) and a capacity of 100 gpm (380 L/min). It features a reseat capability at 90% of its setting and allows back pressure on tank port 2 to be directly additive to the valve setting at a 1:1 ratio. The valve's physical dimensions include a hex size of 1 1/4 inches (31.8 mm) for installation torque between 150-160 lbf ft (203-217 Nm), with an internal hex size of 5/32 inches (4 mm) for adjustment screws, secured by a locknut requiring 80-90 lbf in (9-10 Nm) torque. The model weighs approximately 1.30 lb (0.60 kg).