SUN HYDRAULICS
RPKELCN

***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 RPKELCN (RPKELCN) is a fast-acting, pilot-operated, balanced piston relief cartridge designed to protect hydraulic components from pressure transients. These normally closed, pressure-limiting valves open quickly to manage pressure spikes at the expense of smooth operation. When the inlet port pressure reaches the pre-set threshold, the valve opens to tank port 2, throttling flow to restrict further pressure rise. Its design allows for low-pressure rise versus flow and rapid response times. The RPKELCN can handle maximum pressures at port 2 and is suitable for cross-port relief circuits, though spool leakage should be considered in such applications. It features a 150-micron stainless steel screen protecting the main stage orifice and incorporates Sun's floating style construction to prevent internal binding due to installation torque or machining variations. This model fits into cavity T-18A and belongs to Series 4 with a capacity of up to 200 gpm (760 L/min). The factory pressure settings are established at 4 gpm (15 L/min), with a maximum operating pressure of 5000 psi (350 bar). Typical response time is around 2 milliseconds, while maximum valve leakage at 110 SUS (24 cSt) is approximately 5 in\u00b3/min (80 cc/min) at 1000 psi (70 bar). The valve's adjustment requires about five clockwise turns to increase setting, with a hex size of 1-5/8 inches (41.3 mm) for installation torque ranging from 350 to 375 lbf-ft (474 to 508 Nm). The adjustment screw has an internal hex size of 5/32 inches (4 mm), and the locknut has a hex size of 9/16 inches (15 mm) with a torque specification between 80 and 90 lbf-in (9 to 10 Nm). The model weighs approximately 2.50 lb (1.15 kg), and it uses Viton seal kits like the cartridge version number: 990018006.