SUN HYDRAULICS
RPKELBN

***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 RPKELBN (RPKELBN) is a fast-acting, pilot-operated, balanced piston relief cartridge designed to protect hydraulic components from pressure transients. These valves function as normally closed, pressure-limiting devices that open to tank port 2 when the inlet port 1 reaches the valve setting, throttling flow to manage pressure increases. The RPKELBN offers rapid response at the expense of smoothness and features low pressure rise versus flow characteristics. Physically and functionally interchangeable with other 2-port relief cartridges of the same frame size, it can accept maximum pressure at port 2, making it suitable for cross port relief circuits\u2014though spool leakage should be considered in such applications. The main stage orifice is shielded by a 150-micron stainless steel screen, but this model is not recommended for load-holding applications due to potential spool leakage. Back pressure on tank port 2 adds directly to the valve setting in a 1:1 ratio. The Sun floating style construction minimizes binding risks from excessive installation torque or machining variations. The cartridge fits a T-18A cavity and belongs to Series 4 with a capacity of 200 gpm (760 L/min). Factory pressure settings are established at 4 gpm (15 L/min), with a maximum operating pressure of 5000 psi (350 bar) and typical response time of approximately 2 milliseconds. Maximum valve leakage is rated at 5 in\u00b3/min at 1000 psi (80 cc/min at 70 bar). Adjustment involves up to five clockwise turns, with specific torque requirements for installation and locknut adjustments provided. Weighing approximately 2.50 lb (1.15 kg), it uses Viton seal kits like the cartridge model number: 990018006.