N5 cartridge valves from Parker provide design flexibility for high pressure and high flow applications because they are actually 5-ported cartridges. Each version has 3 work ports, 1 Main pilot port, and one spring chamber vent that can sometimes be used as a second pilot / sense port. Each cartridge contains a spool that is offset by a spring to allow a non-piloted flow configuration. Once pilot pressure is applied to port 1, the spool shifts against the spring creating a second flow configuration. Multiple spool configurations, transition types, and switching pressures are available to cover a wide range of applications. N5A125 and N5A300 cartridge valves have an open transition which connects all 3 work ports together during the shifting of the spool. Both versions operate in the same manner with the key difference being flow rating. The N5A125 is rated for 42 GPM (160 LPM) and the N5A300 is rated for 105 GPM (400 LPM.) They can be used as normally-open, normally-closed and selector directional control valves and in a wide range of pressure and/or flow control circuits. The 5th port spring chamber can be vented to tank or used as a sensing port for applications that require high flow pressure or flow control. Pressure compensation, priority flow control, pressure reducing, pressure relieving, and pressure sequencing are just a few of the applications for these extremely versatile cartridge valves.