Directional control valve

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Directional valves are used in fluid technology ( pneumatics and hydraulics ) to block the path for the working medium ( compressed air , hydraulic fluid ) or to change the direction of flow. The valves differ according to the following main features:

1. Type of control, e.g. B. slide, valve cone
2. Number of switch positions
3. Type of operation, e.g. B. electric (electromagnet), pneumatic, hydraulic, mechanical, manual
4. Number of flow paths
5. Number, size and type of connections, e.g. B. Nominal size, thread

Directional valves are described according to the number of connections per switching position and the number of switching positions. The switch position is indicated in alphabetical order starting from the left with lowercase letters.

Example: A 3/2-way valve (spoken: three-dash-two or often three-two ) has three connections and two switching positions.

Directional control valves are used to control the direction of the volume flow, i.e. H. the extension direction of a cylinder and the length of the stroke controlled by start-stop commands.

Example of a 5/3-way valve (spool type, electromagnetically operated; for hydraulics)

Terminal designations

Circuit symbol of a 5/3-way valve
	Type	Pneumatics: new name	Pneumatics: old name	Hydraulics
	Pressure source	1	P	P
	Working line connection	2, 4	A, B	A, B
	Vent connection or drain	3, 5, 7	R, S, T	R, T (T = tank connection)
	Control connection	12, 14, 16	Y Z	X, Y
	Drain port	-	-	L.