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Meaning of Basic Hydraulic Symbols
Hydraulic symbols are very essential for troubleshooting problems with hydraulic equipment. For any problem related to hydraulic machines, it is necessary to go for a visual inspection of the hydraulic system in question and to study the schematic diagram for the hydraulic circuit. A hydraulic schematic diagram is basically drawings in the form of lines and circles, composed of hydraulic symbols. These symbols indicate the components used in the hydraulic system and how they are interconnected. In other words, hydraulic symbols are used to indicate what type of device is being used in a circuit or in a line.
There are certain basic symbols used in hydraulic systems. These are also same for pneumatic systems. For any one dealing with heavy machinery work around hydraulics or pneumatics, it is better to understand the meaning of these basic hydraulic symbols.
Continuous line: Indicates a flow line.
Dashed line: Indicates a pilot or a drain.
Envelope: Long and short dashes around two or more component symbols.
Large Circle: This symbol indicates motor, pump or a compressor.
Small Circle: This symbol indicates measuring device
Half or Semi Circle: This symbol represents a rotary actuator.
Multiple squares: They are 2 or 3 adjacent squares representing a directional control.
Hydraulic Diamond Symbol: This symbol indicates fluid conditioners, like lubricator, filter, separator or heat exchanger.
Hydraulic Triangle Symbol Triangles in a hydraulic or pneumatic system represent flow direction. There are two types for this. A solid triangle represents hydraulic flow direction, while an open triangle represents pneumatic flow direction.
Parenthesis: It looks like two parenthesis and the curved sides are facing each other. The parenthesis represent flow restriction. Zigzag: The zigzag represents a spring in use.
Conclusion: These are the basic hydraulic symbols . Combining these symbols create "compound" symbols. For example, if we combine the large circle symbol, with a solid triangle pointing out inside it, the compound symbol represent a unidirectional hydraulic pump. Two solid triangles facing outward and opposite each other inside a large circle, means it is a bidirectional hydraulic pump. Similarly when there are more than one squares adjacent to each other in a circuit or line, they represent control valves. If they are stretch to become rectangles, we get cylinders. If a square has an arrow inside, this represent a closed switch. So each symbol when combined with another, represent a hydraulic components. You can check this out at The Important Hydraulic Symbols
There are certain basic symbols used in hydraulic systems. These are also same for pneumatic systems. For any one dealing with heavy machinery work around hydraulics or pneumatics, it is better to understand the meaning of these basic hydraulic symbols.
Hydraulic Line Symbols
There are three different types of lines for hydraulics.Continuous line: Indicates a flow line.
Dashed line: Indicates a pilot or a drain.
Envelope: Long and short dashes around two or more component symbols.
Hydraulic Circular Symbols
There are three different types of circles for hydraulic or pneumatics symbols:Large Circle: This symbol indicates motor, pump or a compressor.
Small Circle: This symbol indicates measuring device
Half or Semi Circle: This symbol represents a rotary actuator.
Hydraulic Square Symbol
Single Square: This represents a pressure control function.Multiple squares: They are 2 or 3 adjacent squares representing a directional control.
Hydraulic Diamond Symbol: This symbol indicates fluid conditioners, like lubricator, filter, separator or heat exchanger.
Hydraulic Triangle Symbol Triangles in a hydraulic or pneumatic system represent flow direction. There are two types for this. A solid triangle represents hydraulic flow direction, while an open triangle represents pneumatic flow direction.
Other Basic Symbols
Zigzag: The zigzag represents a spring in use.
Parenthesis: It looks like two parenthesis and the curved sides are facing each other. The parenthesis represent flow restriction. Zigzag: The zigzag represents a spring in use.
Conclusion: These are the basic hydraulic symbols . Combining these symbols create "compound" symbols. For example, if we combine the large circle symbol, with a solid triangle pointing out inside it, the compound symbol represent a unidirectional hydraulic pump. Two solid triangles facing outward and opposite each other inside a large circle, means it is a bidirectional hydraulic pump. Similarly when there are more than one squares adjacent to each other in a circuit or line, they represent control valves. If they are stretch to become rectangles, we get cylinders. If a square has an arrow inside, this represent a closed switch. So each symbol when combined with another, represent a hydraulic components. You can check this out at The Important Hydraulic Symbols
