1. Standard Grade Technological Studies Pneumatic components: Five port, two state valves

2. 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

3. Five port, two state Valves Also known as a 5/2 valve. Has five ports (air connections) and two states (operating positions)

4. 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.

5. Five port, two state Valves. Port 2 - output connection. This allows the connection of other components that we wish to control.

6. Five port, two state Valves. Port 3 - exhaust. As before, the exhaust is identified by this symbol.

7. Five port, two state Valves. Port 4 - output connection. This allows the connection of other components that we wish to control.

8. Five port, two state Valves. Port 5 - exhaust. As before, the exhaust is identified by this symbol.

9. 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.

10. 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.

11. 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.

12. 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

13. 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. 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.