Hydraulic Symbols (Part 1)

This section presents a list of common hydraulic symbols, hydraulic schematic diagrams which are useful for reading, understanding and interpreting hydraulic schematics and circuit drawings. The following page shows the Working Line-Pressure/Return Hydraulic symbols, Hydraulic Cylinder Symbols, Hydraulic Motors Symbols etc. Check out Significance of Hydraulic Schematic Diagram for more information on hydraulic symbols.

Why hydraulic symbols are used ?

"Hydraulic Symbols" are used to read hydraulic schematics by technicians and students. The varied hydraulic symbols for cylinders, motors, lines, reservoirs, filters, directional valves, control valves, control buttons etc. are illustrated in both line art/engineering drawings and cut-away view drawings. These symbols are used to represent hydraulic components, tools in hydraulic schematic circuits. Technicians/students can easily identify these symbols which help in simplifying the task of visualizing hydraulic circuits. Once visualized, more detailed circuit drawings become easier to read and comprehend.

Check out the meaning of these symbols Meaning of Basic Hydraulic Symbols

Line		Capacity
	Working Line-Pressure/Return		Fixed Capacity with one Direction of Flow
	Pilot Control Line- External/Internal Drain Line		Fixed Capacity with Two Directions of Flow
	Enclosure of two or more functions contained in one unit		Variable Capacity (with Undefined Control Mechanism One Direction of Flow
	Flexible Connection		Variable Capacity (with Undefined Control Mechanism Two Directions of Flow
	Pipe Line Junction		Variable Capacity-Pressure Compensate Pump with One Direction of Flow
	Crossing -Not Connected	Motors
	Hydraulic Source of Energy		Fixed Capacity Uni-Directional Output
	Pneumatic Source of Energy		Fixed Capacity Bi-Directional Output
Direction
	Directions of Flow		Variable Capacity (with Undefined Control Mechanism Uni-Directional Output
	Directions of Rotation		Variable Capacity (with Undefined Control Mechanism Uni-Directional Output
	Facility for Adjustment of: Spring Pump, Solenoid,Cylinder, Damping etc.	Cylinders
	Spring		Single Acting Spring Return (Pneumatic)
	Restriction to flow Line		Double Acting-Single Piston Rod (Hydraulic)
	Power Line Plugged		Double Acting-Double Piston Rod
Connections
	Quick Release-Self Sealing Coupling-Connected (Mechanically opened)		Double Acting-Fixed Cushion at full area side only
	Coupling-Blocked e.g. Gauge Point		Double Acting-Fixed Cushioning at both ends
	Rotary Juction-One Connection		Double Acting-Adjustable Cushioning at both ends (Pneumatic)
	Rotary Juction-Thre Connections		Double Acting Telescopic Cylinder
	Rotary Shaft-Uni-directional		Semi -Rotary Actuator Limited Angle
	Rotary Shaft-Bi-directional
	Shaft-Detent Held
	Pivoting Device
			Next (Part 2)

RELATED ARTICLES

Significance of Hydraulic Schematic Diagram
Meaning of Basic Hydraulic Symbols
Hydraulic Circuit Diagrams: Importance and True Value