Standard Grade Technological Studies

Pneumatic components:Five port, two state valves

Problems using 3/2 Valves

• We can control a double acting cylinder with two 3/2 valves.

• It is easy to push or pull the piston.• This is because there is not a constant air supply to

the cylinder• Air is free to escape from a 3/2 valve when it is not

actuated

Five port, two state Valves

• Also known as a 5/2 valve.

• Has five ports (air connections)

• and two states (operating positions)

Five port, two state Valves

• Like the 3/2 valve, each port is numbered to help us make the correct connections.

• Port 1 - main air.

• Remember, main air is identified by this symbol.

Five port, two state Valves

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• Port 2 - output connection.

• This allows the connection of other components that we wish to control.

Five port, two state Valves

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• Port 3 - exhaust.

• As before, the exhaust is identified by this symbol.

Five port, two state Valves

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• Port 4 - output connection.

• This allows the connection of other components that we wish to control.

Five port, two state Valves

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• Port 5 - exhaust.

• As before, the exhaust is identified by this symbol.

Five port, two state Valves

• State 1 - instroke

• Air flows from port 1 to port 2, this instrokes the cylinder.

• Air will also flow from port 4 to port 5.

• The diagram shows the flow of air in this state.

1

2

3

4

5

AIR FROMCYLINDER

AIR TOCYLINDER

Five port, two state Valves

• State 2 - outstroke• This time air flows from port

1 to port 4, making the cylinder outstroke.

• Again air flows from the other output connection, port 2 to the exhaust port 3.

• As before the diagram shows the flow of air in this state.

1

2

3

4

5

AIR FROMCYLINDER

AIR TOCYLINDER

Pilot air

• 5/2 valves can be actuated in a similar manner to 3/2 valves.• A more common and useful method is to use a Pilot Air Signal.• A pilot air 5/2 valve will change state when a brief air signal acts

at either end of the valve.• This pilot signal is usually provided by using 3/2 valves.

Valve A

Assignment 6

1. Our car park barrier is gradually improving. The circuit has been changed to look like the one shown previously.

• Build and test the circuit.• Produce a list of all the components used.• Describe how the circuit works

Valve A

Assignment 6

2. A door entry system is controlled by pneumatics. The system makes use of a double acting cylinder. Part of the circuit diagram is shown.

A

B

C• Name each of the components A, B and C.

• Copy and complete the circuit diagram so that the door will open and close.

• Describe how the circuit operates.