Standard Grade Technological Studies

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

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Five port, two state Valves

• Also known as a 5/2 valve.
• Has five ports (air connections)
• and two states (operating positions)

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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.

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Five port, two state Valves
.

• Port 2 - output connection.

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

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Five port, two state Valves
.

• Port 3 - exhaust.

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

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Five port, two state Valves
.

• Port 4 - output connection.

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

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Five port, two state Valves
.

• Port 5 - exhaust.

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

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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.

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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.

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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.

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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

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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.