SUN HYDRAULICS
RELIEF CART
RBAELWN

***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 RBAELWN (RBAELWN) is a two-port, pilot-stage, direct-acting relief cartridge that functions as a fully adjustable, normally closed pressure-regulating valve. Designed to open a flow path from port 1 to port 2 when the inlet pressure exceeds the spring force setting, this cartridge is ideal for integration with Sun's main stage pilot or vent-to-operate cartridges. It utilizes the Sun T8A two-port cavity, simplifying installation by eliminating separate pilot lines and requiring only one cavity for both control and primary functions. Both ports can be pressurized up to 5000 psi (350 bar), making it suitable for high-pressure applications. The valve's construction features a hardened poppet and seat, ensuring consistent operation with low leakage rates and superior wear resistance. Notably, backpressure at the port 2 outlet adds directly to the pressure setting at port 1 inlet. Cartridges configured with EPDM seals are specifically designed for systems using phosphate ester fluids; exposure to petroleum-based fluids will damage these seals. This product incorporates Sun's floating style construction to reduce the risk of internal parts binding due to excessive installation torque or machining variations in cavity/cartridge configurations. The RBAELWN has a capacity of 2.5 gpm (10 L/min) and operates at maximum pressures of 5000 psi (350 bar). It boasts a typical response time of 2 ms and minimal valve leakage at 110 SUS (24 cSt) with only 15 drops/minute (1 cc/minute). The valve hex size measures 7/8 inch (22.2 mm), requiring an installation torque of between 20-25 lbf ft (27-33 Nm). The adjustment screw has an internal hex size of 5/32 inch (4 mm), while the locknut requires a hex size of 9/16 inch (15 mm) and torque between 80-90 lbf in (9-10 Nm). A Viton seal kit is available under part number 990608006 for additional maintenance needs.