SUN HYDRAULICS
RELIEF CART
RPGELWN

***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 RPGELWN (Material Number: RPGELWN) is a fast-acting, pilot-operated, balanced piston relief cartridge designed to protect hydraulic components from pressure transients. It is normally closed and functions as a pressure-limiting valve, opening rapidly when the inlet port pressure reaches the set value to throttle flow to tank port 2, thereby limiting pressure rise. This valve offers low pressure rise versus flow and is characterized by its rapid response time of approximately 2 milliseconds. Although it features fast operation, it may sacrifice smoothness in performance. The RPGELWN model is interchangeable with other 2-port relief cartridges of the same frame size and flow path but is not suitable for load-holding applications due to potential spool leakage. The valve accepts maximum pressure at port 2, making it suitable for cross-port relief circuits; however, users should consider spool leakage in such applications. Its main stage orifice benefits from a protective 150-micron stainless steel screen. The backpressure on tank port 2 directly adds to the valve setting at a 1:1 ratio. Configurations with EPDM seals are compatible with phosphate ester fluids but are vulnerable to damage from petroleum-based substances. Installation requires specific torque settings: an installation torque of 45-50 lbf ft (61-68 Nm), an adjustment screw internal hex size of 5/32 inches (4 mm), and a locknut torque between 80-90 lbf in (9-10 Nm). The cartridge incorporates Sun's floating style construction to minimize binding risks due to excessive installation torque or cavity machining variations. With a capacity of up to 50 gpm (200 L/min) and maximum operating pressure of 5000 psi (350 bar), this robust valve ensures reliable performance in high-pressure hydraulic systems.