The switching time (either opening or closing) of 2-way cartridge valve can be influenced by installing orifices in the pilot lines. The orifices restrict the flow rate of pilot flow to and from the pilot area of the cartridge valves.
Orifice (Nozzle) in D1: The pilot oil in port X can be throttled by the use of an orifice D1. This will influence only the closing time.
Orifice (Nozzle) in D2: The pilot oil is flowing in both directions, to and from the spring chamber through the orifice D2 and will influence both, the opening and closing time.
Orifice (Nozzle) in D3: The pilot oil flow from the spring chamber is throttled by D3 and will only influence the opening time. Care should be taken to verify Tank Port Pressure ratings in the directional control valve.
The size of the orifice required depends upon the volume of the spring chamber, the required switching time, and the pressure drop across each orifice.
For information on cartridge valve sizing, please refer to the documentation available on our website on cartridge valves.
Robert Roithner has been with Moog since 1996. His career started as a hydraulic engineer in 1964 and he is one of the fathers of the modern hydraulic cartridge technology. He has experience in many different engineering and management functions involving hydraulic systems in Europe and USA. Currently he is working for the Systems Group Moog GmbH.