The following symbols are generally in accordance with BS 1553-1...and BS 5070
Different Line Types.
Different Pipe Supports.
Symbols for Fitting and Representations.
Symbols for Valves
Symbols for Valve Actuators.
Symbols for Instruments.
|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 level of detail for the equipment relates to the type of schematic being produced. A Process Flow Sheet will only show the basic level of information sufficient to show the essential process flowpaths. An Engineering Line Diagram of P & ID drawing will show a much more detailed representation.
Line Tags and Equipment Identification.
Reading Pneumatic Schematic Symbols
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 symbolizes the possible valve functions orpositions. Example: A 5/2 valve schematic will be illustrated with 2 blocksdescribing two valve functions or positions/ A 5/3 valve schematic will show threeblocks describing 3 possible valve functions.
Pneumatic valves can be operated in several ways. Handoperated (including levers and push and or push pull buttons) : Air piloted(operated remotely by pneumatic signals) : Solenoid (directly actuated withelectronic signals)
Exhaust Port Symbol
The inverted triangle symbol Denotes an exhaust port.The letters EA indicate this is the exhaust port for the A circuit. Ebin turnindicated the exhaust port for the B circuit.
The arrow symbols illustrate the direction of gassesflowing 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 toport A or B as shown by the arrows.
The return spring
The spring symbol defines the “at Rest” position ofthe solenoid valve. The spring “pushes” from the side it is drawn on and placesthe right side block diagram of the valve in function.
The T Symbol
This symbol indicates that a port is closed and isneither passing or exhausting gas.
Pressure of air supply symbol
This symbol indicates the air supply port, in addition tothis the letter P or the number 1 also indicated the air supply port.