HYDRAFORCE DIRECTIONAL CONTROL VALVE EV20-S34-16T-N-80
New, Hydraforce. A spool-type, screw-in, cartridge-style, hydraulic directional element, with multifunction potential when used with other directional, pressure, or flow control devices. The EV20-S34 is a spring-biased blocking valve which will shift to allow full flow from 1 to 2 only when port 3 is vented to create a pressure drop across the internal orifice which exceeds the pressure of the bias spring force. EV20-S34 is a vent-to-open directional valve.
Type Vented, Spool Type, Logic Element Directional Control Valve
If I am reading everything correctly. This valve 9-ev20-s34-16t-n-80 is primarily a dump valve? If everything is plumbed correctly you should have full pressure and flow to a cylinder on the extension. When the cylinder retracts it should have full flow of the valve, with minimal pressure since it takes 80psi to open the valve and then would be vented to the hydraulic tank. I hope I'm reading this correctly, if not i will need pointed in a better direction. Thanks for your time. Chris
A: This valve only appears to open if the pressure differential exceeds the spring bias to open the passage (when port 3 is vented to provide the pressure drop). That venting would have to be controlled by yet another valve. It's function is similar to that of an electrical relay, in a sense. While it could work as a dump valve, it's really made for a more specialized application.