This section shows some of the many instrument symbols found in different types of technical diagrams used to document instrument systems.
7.5.1 Line types
![](https://www.technocrazed.com/books/Instrumentation/Book_half1083x.png)
Note: the single backslash signifying a “discrete” or “binary” signal type has been removed from the ISA standard as of the 2009 ANSI publication. Regular pneumatic and electrical line symbols may represent either continuous or discrete states. The “triple-slash” alternative linetype for electrical symbols is also absent from the 2009 ANSI/ISA standard.
7.5.2 Process/Instrument line connections
![](https://www.technocrazed.com/books/Instrumentation/Book_half1084x.png)
7.5.3 Instrument bubbles
![](https://www.technocrazed.com/books/Instrumentation/Book_half1085x.png)
7.5.4 Process valve types
![](https://www.technocrazed.com/books/Instrumentation/Book_half1086x.png)
7.5.5 Valve actuator types
![](https://www.technocrazed.com/books/Instrumentation/Book_half1087x.png)
7.5.6 Valve failure mode
![](https://www.technocrazed.com/books/Instrumentation/Book_half1088x.png)
7.5.7 Liquid level measurement devices
![](https://www.technocrazed.com/books/Instrumentation/Book_half1089x.png)
7.5.8 Flow measurement devices (flowing left-to-right)
![](https://www.technocrazed.com/books/Instrumentation/Book_half1090x.png)
![](https://www.technocrazed.com/books/Instrumentation/Book_half1091x.png)
7.5.9 Process equipment
![](https://www.technocrazed.com/books/Instrumentation/Book_half1092x.png)
7.5.10 Functional diagram symbols
![](https://www.technocrazed.com/books/Instrumentation/Book_half1093x.png)
7.5.11 Single-line electrical diagram symbols
![](https://www.technocrazed.com/books/Instrumentation/Book_half1094x.png)
![](https://www.technocrazed.com/books/Instrumentation/Book_half1095x.png)
7.5.12 Fluid power diagram symbols
![](https://www.technocrazed.com/books/Instrumentation/Book_half1096x.png)
![](https://www.technocrazed.com/books/Instrumentation/Book_half1097x.png)