In circuit diagrams, solenoid valves are represented by dedicated symbols. Depending on the valve design, different symbols are used to distinguish the operating principle, function, and actuation method.
| WW | Actuation | Function | Special Features |
| A | Direct acting | 2/2-way valve, normally closed (NC) | |
| A | Pilot operated | 2/2-way valve, normally closed (NC) | Internal pilot channel |
| A | Assisted lift (servo assisted) | 2/2-way valve, normally closed (NC) | Internal pilot channel with forced diaphragm lift at low differential pressures |
| A | Externally pilot-operated | 2/2-way valve, normally closed (NC) | Actuated by an external pilot; piston or diaphragm operated, e.g. by compressed air |
| B | Direct acting | 2/2-way valve, normally open (NO) | |
| B | Pilot operated | 2/2-way valve, normally open (NO) | Internal pilot channel |
| B | Assisted lift (servo assisted) | 2/2-way valve, normally open (NO) | Internal pilot channel with forced diaphragm lift at low differential pressures |
| B | Externally pilot-operated | 2/2-way valve, normally open (NO) | Actuated by an external pilot; piston or diaphragm operated, e.g. by compressed air |
| C | Direct acting | 3/2-way valve, normally closed (NC) | Exhaust through the guide tube or design with all ports integrated in the valve body |
| D | Direct acting | 3/2-way valve, normally open (NO) | Inlet through the guide tube or design with all ports integrated in the valve body |
| E | Direct acting | 3/2-way valve, mixing function | One inlet through the guide tube or design with all ports integrated in the valve body |
| F | Direct acting | 3/2-way valve, diverting function | One outlet through the guide tube or design with all ports integrated in the valve body |
| C-F | Pilot operated, assisted lift or externally pilot-operated | Implementations available | Design according to customer specification |
