SUN HYDRAULICS Normally closed, balanced poppet, logic element with integral T-8A control cavity - vent-to-open (DKJR8HN)

This is a normally closed, balanced poppet, switching element with an integral T-8A control cavity. With a 2-way valve in the closed position installed in the T-8A control cavity, the poppet remains closed. Opening the 2-way valve shifts the poppet to the open position, provided there is sufficient pressure at port 3. Unique balanced construction provides predictable switching with 5000 psi (350 bar) at port 1 and port 2. Switching will only occur when both a minimum pilot pressure of 400 psi (30 bar) is present and pilot control valve is open. These valves are hydraulically balanced between port 1 and port 2. Port 1 and port 2 are fully sealed from port 3 and port 4. Ports 3 and 4 are positively sealed. Any backpressure at the drain port is directly additive to the required pilot pressure for reliable operation. Leakage rate between port 1 and port 2 is very low, typically less than 10 drops/min. at 5000 psi (0,7 cc/min at 350 bar). Valve will reseat when the pilot pressure falls below 145 psi (10 bar).