Check, Directional and Flow Restrictor Functions

Check, Directional and Flow Restrictor Functions

Cartridge valves for directional and check functions are essentially hydraulically piloted check valves. Control options include single or multiple pilot arrangements, flow restrictors, and solenoid controlled, pilot operated directional control. Grouping cartridge assemblies (selected individually according to flow requirements) for control by one or more common pilot valves can provide directional, check and/or flow restrictor functions for normal flow rates up to 3650 L/min (965 USgpm) per cartridge. Typical single cartridge arrangements are symbolized on the following pages, and your Eaton-Vickers representative can illustrate various grouped arrangements. Basic poppets are illustrated. Others provide flow restrictions between ports A and B and internal pilot orificing between port A and spring chamber AP. Poppets can be combined with different springs to provide three different cracking pressures.

Pressure Ratings

Maximum pressure allowable at ports A and B is 350 bar (5000 psi) for all cartridges. Minimum pressure is 0,3 to 5 bar (4.4 to 72 psi), dependent on the poppet/spring combination. The maximum pressure limit at pilot ports X, Z1, Z2 and AP and pilot valve interface ports P, T, A and B is generally 350 bar (5000 psi), dependent on the limit of any associated pilot valve or module.

Pilot port Y maximum pressure limit is also 350 bar (5000 psi). However, port Y is normally used as the pilot drain port, when it should be connected directly to the reservoir. In many functions any pressure at port Y is additive to the set opening/ cracking pressure of the cartridge.

Remote Pilot Operated Functions

Remote piloted arrangements (pilot not integrally mounted on cartridge cover) require the application of pilot flows and pressures appropriate to the application and within the limits of any associated pilot valves and modules, whichever have the lower limits.