SUN HYDRAULICS
RDHALSV

***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 RDHALSV (Material Number: RDHALSV) is a direct-acting relief cartridge valve designed to protect hydraulic systems from pressure transients by limiting pressure rise. It operates by opening to tank port 2 when the inlet port 1 reaches a set pressure, throttling flow to maintain safe pressure levels. This valve is known for its smooth operation, zero leakage, dirt tolerance, and rapid response time of typically 2 milliseconds. It features a floating style construction that minimizes internal binding due to installation torque or machining variations. The RDHALSV can handle a maximum operating pressure of 5000 psi (350 bar) and has a capacity of 100 gpm (380 L/min). It is suitable for use in cross-port relief circuits and load-holding applications, accepting maximum pressure at port 2 with backpressure directly additive to the valve setting in a 1:1 ratio. The adjustment screw seals are exposed to system pressure, requiring the system to be depressurized before adjustments can be made. The valve's performance remains stable despite changes in oil temperature or contamination levels. For optimal repeatability, select a spring range where the desired relief setting falls between midrange and high within the minimum and maximum limits. Installation requires specific torques: 150-160 lbf ft (203-217 Nm) for the valve installation and 80-90 lbf in (9-10 Nm) for the locknut. The adjustment screw has an internal hex size of 5/32 inches (4 mm), while the locknut hex size is 9/16 inches (15 mm). This model weighs approximately 1.30 lb (0.60 kg) and utilizes Viton seals with part number 990316006 for maintenance or replacement needs.