SUN HYDRAULICS
RPGELDN

***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 RPGELDN (RPGELDN) is a fast-acting, pilot-operated, balanced piston relief cartridge designed to protect hydraulic components from pressure transients. This normally closed, pressure-limiting valve opens rapidly when the inlet port 1 reaches the set pressure, diverting flow to tank port 2 to limit further pressure rise. The RPGELDN is characterized by its low-pressure rise versus flow and quick response time of approximately 2 milliseconds. It is suitable for use in cross-port relief circuits due to its ability to accept maximum pressure at port 2; however, users should consider spool leakage in such applications. The main stage orifice is safeguarded by a 150-micron stainless steel screen, ensuring reliable operation. This model features Sun's floating style construction that minimizes internal binding risks during installation or due to machining variations in the cavity/cartridge interface. This valve has a capacity of 50 gpm (200 L/min) and can handle a maximum operating pressure of 5000 psi (350 bar). It is not recommended for load-holding applications because of potential spool leakage. The RPGELDN operates with EPDM seals suitable for phosphate ester fluids but should avoid petroleum-based fluids that could damage the seals. The backpressure on tank port 2 directly adds to the valve setting at a 1:1 ratio. Installation requires specific torque settings: valve installation torque ranges from 45-50 lbf ft (61-68 Nm), while locknut torque ranges from 80-90 lbf in (9-10 Nm). The adjustment screw features an internal hex size of 5/32 inches (4 mm), and adjustments are made via clockwise turns to increase settings up to five turns.