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
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
7.5.3 Instrument bubbles
7.5.4 Process valve types
7.5.5 Valve actuator types
7.5.6 Valve failure mode
7.5.7 Liquid level measurement devices
7.5.8 Flow measurement devices (flowing left-to-right)
7.5.9 Process equipment
7.5.10 Functional diagram symbols
7.5.11 Single-line electrical diagram symbols
7.5.12 Fluid power diagram symbols
