Pneumatic Components and Symbols

Pneumatic symbols are used to describe the function of the various valves and other devices which are connected together to form circuits and sub circuits.

Symbols for valves are shown as boxes representing the dfferent operating positions - the symbol shown for example is based on two boxes so it is a two position, or 2-stage, valve. Looking at any one of the boxes gives an indication of the number of ports on the valve - in this case there are 2 ports in each box (i.e. at centre top and bottom) so it would be a 2-port, 2-stage valve (2/2 Valve).

In the left-hand box, the arrow indicates that both ports are open and air would be allowed to pass through the valve in this position. In the right-hand box, the same two ports are shown as blocked. In this position, air is not allowed to pass.

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Component		Name and Description			Symbol
	Compressor	The symbol shown is that for the Main Air Supply which is normally supplied by a compressor.
	Receiver	The air produced by the compressor is stored in a vessel called the receiver or reservoir. The function of the receiver is to store the air for future use, to smooth pressure spikes and to allow water to fall out of the air to the bottom of the tank where it can be drained.
		Air Pipes Connected	The air produced by the compressor is distributed by air lines or pipe-work to the points where it is required.
		Air Pipes Not Connected	In a factory the pipe-work is run downhill in a further attempt to remove excess water from the system.