Hydraulic systems are an indispensable part of industry and manufacturing. Symbols of Hydraulic Valves are important tools in the hydraulic system. The symbols are helpful for engineering design, understanding, and maintenance. If you want to understand the hydraulic system deeply, these symbols are the essential learning content.
Basic graphics of hydraulic valve symbols
1 Square box
The square boxes represent each working position of the valve, so it is also called a function box. Each square has oil passages drawn inside it, showing the direction of flow at that location. When several boxes are arranged side by side, it indicates that the valve has multiple switching states.
2 Arrow
Arrows are used to represent the direction of oil flow. Solid arrows indicate normal fluid flow direction, while dashed arrows may imply fluid leakage or other problems.
3 Letter
In hydraulic valves, the letters such as T, P, A, B, etc, are used to indicate the valve interfaces. T represents the return oil port. P represents the pressure oil port. A, B represent the working port, which accesses the execution unit. X, Y represent the pilot control port.
4 Spring
Serrated lines are used to represent springs. Springs are an important and common element in hydraulic system symbols. When this symbol appears, it indicates that the valve core is a spring-return type.
5 Lines
Lines in hydraulic valve symbols generally represent control lines or hydraulic lines. For example, solid lines indicate the direction of hydraulic flow, and dotted lines indicate the control signal line. When you see a symbol enclosed by a thin solid line in a hydraulic diagram, it indicates the overall structure of a valve.
Classification of Hydraulic Valves Symbols
1 Hydraulic directional control valve symbol
Directional control valves are common valves in hydraulic systems, which control the direction of oil flow. It includes 2-way-2-position valve, 3-way-2-position valve, 4-way-2-position valve, and 4-way-3-position valve. The symbols for these valves are shown in the figure below.
2 Hydraulic pressure control valve symbol
Hydraulic pressure control valves are used to control the pressure value in the system. It mainly includes a pressure relief valve, a pressure reducing valve, a pressure sequence valve, counterpressure overcenter valve. Their symbols are shown below.
3 Hydraulic check valve symbol
Check valves allow oil to flow in only one direction. It is divided into two types: a check valve and pilot pilot-operated valve. As shown in the figure below.
4 Hydraulic flow control valve symbol
This valve is used to control the flow of oil, therefore regulating the speed of the actuator. It concludes the flow control variable throttling valve and compensated flow regulator valve. The symbols of hydraulic flow control valves are shown in the figure below.
The Function of Hydraulic Valve Symbols
Symbols are a general language in a hydraulic system. You can use these symbols to communicate with others efficiently. Understanding hydraulic valve symbols can help you design the correct hydraulic system. At the same time, hydraulic valve symbols also play an important role in maintenance.
How to Master Hydraulic Valve Symbols
If you want to master hydraulic valve symbols, you first need to learn the symbols for basic components. When reading hydraulic valve symbols, pay attention to the number of valve positions to identify the valve status. At the same time, you should clearly see the number of channels in the hydraulic valve and pay attention to the working mode in the hydraulic valve symbol. All of these will help you better understand a hydraulic valve working diagram. Reading some related books may also be helpful.
