By Miles Nicholson
Nowadays, many customers are not only responsible for producing the electrical drawings but also the instrument or pneumatic drawings as well. A job may have a mixed discipline and may include pneumatic and electrical schematics.
In this type of situation, a component may be drawn in the pneumatic drawing such as a valve and have an associated solenoid defined in the electrical schematic. These types of components would be defined as “parent” devices. However, because there is an international convention for numbering pneumatics and hydraulics (ISO1219 as an example), the component in the pneumatic circuit would have an entirely different component tag to the one in the schematic.