Device used to control or the output of the fluid by influencing the start, stop and direction, as well as the pressure and/or flow rate of the pressure fluid acting in the system (Figure V 3).
Valves are differentiated according to:
- task: directional, pressure, flow and check valves (Figure V 4),
- design: seated valves (conical, ball and disc seated valves), (lengthwise) and rotary valves (Figure V 5),
- working method: specified switching positions (2-position directional valves, check valves, 3-position and multiple position directional valve), adjustable working position (throttle, flow control valves, pressure valves) and continuously adjustable working position (manually operated directional valves), continuously adjustable valves),
- controlled ports: 2-way, 3-way, 4-way valves and more;
- actuation (types): manual, mechanical, pressure (hydraulic, pneumatic), electrical actuation.
Figure V 3: Control with the most important valves
Figure V 4: Tasks of the valve functions
Figure V 5: Principles of valve mounting