Pneumatics - way valves

Naming pneumatic way valves

The choice of a directional control valve depends on e.g.  which cylinder you are using, which actuation is to be implemented, whether this valve is to be actuated directly or indirectly.But for all valves aplies: the naming depends on the number of connections and switch positions.

Animation: 2/2 valve

Animation: 2/2 valve


Connecting way-valves: The names of the connections, which are standardized, you get in the following table:

new designation                                                   old designation   
1          compressed air connection
3, 5      venting
4, 2      working lines to the actor
12, 14  control connections
1 = activated, 0 = centered, 2 activated(in case of 3 switching positions)
P
R
A, B
Z, Y
a, 0, b

3/n-way valve only have one connection to the actor therefore are used for single-acting cylinder; 5/n-way valves accordingly for double-acting cylinders.

pneumatic way valves

pneumatic way valves


Basic position:

The basic position or normal position of the valve is called the position of the internal elements when the valve is not actuated. It is usually represented by the right rectangle of the symbol:

- Normal closed valve (NC) that does not allow airflow in itsnormal position.

Way-valve normally closed NC

Way-valve normally closed NC

- Normal open valve (NO) that allows airflow in its normal position.

Way-valve normally opened NO

Way-valve normally opened NO


5-2 way impulse valve and its logic diagram

5-2 way impulse valve and its logic diagram

Pulse-way valves which remain their position: You can classify directional control valves according to their characteristics. Spring return valves jump immediately after being activated back to their initial position. Pulse valves on the other hand keep the momentary switch position after being activated. This property can be illustrated clearly by logic diagram:

 

 

Exercises:

A1:

3-2 way valve

3-2 way valve

Name the way valve with the symbol aside!

 

 

A2:

5-2 way valve

5-2 way valve

 

Find the correct naming and symbol for this way valve!