Common Solenoid Valve and other Pneumatic symbols.

a detailed view of pneumatic circuit symbols and their meaning. Valve symbols including solenoid valve symbols are those that are in common use. Solenoid Valve Symbols:

2/2 valve - 2 ports 2 positions
3/2 valve - 3 ports 2 positions

4/2 valve - 4 ports 2 positions

 5/2 valve - 5 ports 2 positions

 5/3 valve - 5 ports 3 positions


 Air Dryer

Air Motor - flow one direction

 Air motor - flow two directions
Check Valve - spring closed

 Cylinder - Spring return

 Cylinder - Double Acting with double rod
 Cylinder - Double acting with single fixed cushion

Cylinder - Double acting with two adjustable cushions

Differential pressure

Direction of flow

Exhaust Line - control line
Filters and Regulators

Filter with automatic drain

Filter with manual drain

Fixed restriction

 Flexible hose line

 Flow control valve
Flow Gauge

Line Connected

Lines crossing

Muscular Control
 One bypass flow valve and two closed ports  
One flow path

 Pedal or treadle
 Pilot pressure - external
 Pilot pressure - Internal

Plugged Port

Plunger or Position Indicator


Pressure Actuated Switch
Pressure Gauge
Pressure Regulator - Non Relieving

Pressure Regulator - Self Relieving
 Push Button
Quick Connect Coupling
Roller One Way

Shuttle Valve
Solenoid with pilot and manual over ride
Solenoid - Single Winding
Two Closed Ports

Two distinct positions and one transitory position
Two flow paths
Two flow paths with cross connection
Vacuum Pump
Variable Restriction
Working Line

The following symbols are generally in accordance with BS1553-1 and BS5070Different Line Types.

Pipe Support Symbols

Symbols for fitting and representations.

Symbols for Valves

Symbols for Valve Actuators

Symbols for Instruments

Symbols for Flow Instruments

Instrument Indentifiers

Measured Variable

Type of Conditioner

Type of Component

F = Flow

R = Recorder

T = Transmitter

L = Level

I = Indicator

M = Modifier

P = Pressure

C = Controller

E = Element

Q = Quantity

A = Alarm


T = Temperature


Connexion Solenoid Valve symbols from the UK's premier solenoid valve suppliers

Symbols for Process Equipment

The levels of detail for process equipment relates to the schematic type produced. A process flow sheet will only show basic levels of technical information sufficient to highlight essential process flow paths. An engineering line diagram of P and ID will show a lot more detailed comprehensive information and technical detail.

Equipment Process Plant -1

Equipment Process Plant - 2

Line tags and equipment identification.

Reading Pneumatic Schematic Symbols

 Valve Symbol
5/2 Valve has 5 ports and 2 possible conditions
1.) B is pressurized and A is exhausted.
2.) A is pressurized and B is exhausted.
When the solenoid is NOT energized the B port is pressurized. The spring symbol defines the valve position at rest.
The Block
Solenoid Drawing
The block symbolizes the possible valve functions or positions. Example: A 5/2 valve schematic will be illustrated with 2 blocks describing two valve functions or positions/ A 5/3 valve schematic will show three blocks describing 3 possible valve functions.
The Actuator.
Valve Drawing Symbol
(Solenoid) Symbol
Pneumatic valves can be operated in several ways. Hand operated (including levers and push and or push pull buttons) : Air piloted (operated remotely by pneumatic signals) : Solenoid (directly actuated with electronic signals)
Exhaust Port Symbol
Valve CAD Symbol
The inverted triangle symbol Denotes an exhaust port. The letters EA indicate this is the exhaust port for the A circuit. Ebin turn indicated the exhaust port for the B circuit.
The Arrows
SV Symbol
The arrow symbols illustrate the direction of gasses flowing into and out of the valve ports. Gas pressure is supplied from port P. Depending on which of the valve blocks is in function, the gas is directed to port A or B as shown by the arrows.
The return spring
Solenoid Drawing
The spring symbol defines the “at Rest” position of the solenoid valve. The spring “pushes” from the side it is drawn on and places the right side block diagram of the valve in function.
The T Symbol
Solenoid Drawing
This symbol indicates that a port is closed and is neither passing or exhausting gas.
Solenoid Drawing
Pressure of air supply symbol
This symbol indicates the air supply port, in addition to this the letter P or the number 1 also indicated the air supply port.