Hydraulic and pneumatic symbols are standardised graphical symbols used in engineering diagrams to represent components such as valves, pumps, cylinders, and control systems. These symbols follow ISO 1219 and allow engineers to design, interpret, and troubleshoot fluid power systems consistently.
Hydraulic and pneumatic symbols are used to show how fluid power systems operate. Each symbol represents a component or function within a circuit, such as flow control, pressure regulation, or energy conversion.
Hydraulic and pneumatic circuit symbols are used to represent components and systems in fluid power engineering diagrams. These standardised symbols allow engineers to interpret and design systems consistently across industries. This page provides a reference to commonly used symbols based on ISO 1219 and related standards.
The symbols shown below are generally based on
BS 2917-1:1993, ISO 1219-1:1991. Graphic symbols and circuit diagrams for fluid power systems and components. Specification for graphic symbols
Note: This is one standard identified by two numbers.
For information on production of circuit diagrams refer to
BS ISO 1219:1995. Fluid power systems and components. Graphic symbols and circuit diagrams. Circuit diagrams
Diagrams of pneumatic and hydraulic components are produced using these symbols as building blocks, combining functional symbols with symbols for variability and operation.
Following are examples of the basic symbols
This chart shows common hydraulic and pneumatic symbols used in engineering drawings, including valves, actuators, pumps, and control elements.
Basic hydraulic and pneumatic symbols used in ISO 1219 circuit diagrams
Following are typical symbols associated with valve operators
Hydraulic valve operator symbols diagram engineering used in ISO 1219 circuit diagrams
Following are typical symbols associated with pumps and motors
Pump and motor hydraulic symbols diagram engineering used in ISO 1219 circuit diagrams
Following are typical symbols associated with instruments
Hydraulic instrumentation symbols diagram engineering used in ISO 1219 circuit diagrams
Following are typical symbols associated with fluid conditioning units
Fluid conditioning symbols symbols diagram engineering used in ISO 1219 circuit diagrams
Following are typical symbols associated with fluid cylinders
Hydraulic cylinder symbols symbols diagram engineering used in ISO 1219 circuit diagrams
Following are typical symbols associated with fluid system pressurisation
System pressurisation hydraulic symbols symbols diagram engineering used in ISO 1219 circuit diagrams