When interacting with hydraulic systems, you may have seen tiny pictograms on certain components. These tiny lines and shapes are virtually a secret language, only known by a tiny minority.
Underneath, we help you decipher these symbols to help you optimize the performance of your hydraulic system.
Hydraulic Symbols Explained
Hydraulic symbols are essentially regularized shorthand codes that symbolize varying components of your hydraulic system as well as their respective functions.
They are typically known as the hydraulic alphabet and they are explained in the ISO 1219-1:2012 handbook. Although, these symbols may seem quite complicated, deciphering their meaning becomes easier once you get used to them.
Hydraulic Components and Their Respective Symbols
Attempting to decipher hydraulic symbols without proper understanding is like attempting to work out a puzzle without the requisite pieces. Beneath, we look at the varying hydraulic components and their respective symbols.
· Hydraulic Pump Symbols
This symbol depicts a hydraulic pump that rotates unidirectionally and has a fixed displacement.
This symbol depicts a hydraulic pump with a fixed displacement and can support rotation in several directions. This is evidenced by the presence of two arrows inside the circle.
This symbol features an arrow pointing outwards and this arrow depicts the unidirectional flow of your hydraulic fluid. The other arrow shows that you can adjust the displacement of your hydraulic pump.
Comprising a hand symbol, this graphic depicts the level of human intervention involved in activating this pump. It also features a pump symbol.
This symbol features two directional arrows indicating that your hydraulic fluid can flow in two distinct directions. It also features a variable arrow, which shows that you can adjust the displacement of your hydraulic pump.
· Hydraulic Cylinder Symbols
This hydraulic cylinder symbol is characterized by a rectangular shape with an arrow showcasing your working stroke’s direction.
Comprising a rectangular body, which represents your hydraulic cylinder, this symbol shows that you can inject your hydraulic fluid into your cylinder from either side. Once you come through a cylinder with this marking, you can utilize it in hydraulic presses.
This symbol features a wavy line, which symbolizes the spring in your hydraulic cylinder. This spring is responsible for the return stroke.
This symbol comes with two distinctive rods protruding from both ends of your cylinder. These rods symbolize the bidirectional control that comes with these types of hydraulic cylinders.
This symbolizes a hydraulic cylinder capable of exerting force and pressure in two distinct directions. The graphic comes with two rods, which signify the additional stability of these cylinders.
This hydraulic cylinder symbol has only one bar unlike the double-cushioned one. As such, this cylinder can absorb a significant impact on one side.
· Hydraulic Motor Symbols
The motor simply provides the torque that runs your hydraulic system. In hydraulic schematics, this component is represented uniquely. Here are some of its prominently used symbols:
This hydraulic motor only rotates in a singular direction and has a fixed displacement. The output speed of this motor matches your input flow rate.
This hydraulic motor symbol features a line that cuts across the motor symbol and this line represents the variable displacement trait of this motor. When using this type of motor, you can adjust its displacement, consequently impacting your output speed.
The bidirectional arrows on this symbol indicate your motor’s ability to rotate clockwise and anticlockwise.
Motors symbolized by this sign boast of bidirectional rotation as well as an adjustable output speed. This symbol features a variable displacement line as well as two arrows, which signify bidirectional movement.
· Hydraulic Rotary Actuator Symbol
Although this actuator is typically categorized as a hydraulic motor, the rotary actuator only operates within a particular angular range. Its symbol comprises a curved shaft, a solid triangle, and an inward-pointing arrow, as depicted above.
· Hydraulic Valves Symbols
Any successful turn, lift, or press executed by your hydraulic system relies on a myriad of interconnected hydraulic valves. These distinct valves are typically identified by their unique symbols in hydraulic schematics. These symbols include:
· Hydraulic Accessories Symbols
Hydraulic accessories do not get the attention they deserve and this might be because they play a behind-the-scenes role. However, these overlooked gadgets significantly impact the performance of your hydraulic system. They are often represented by the following symbols:
Let’s start with hydraulic accumulator:
· Hydraulic Connections and Lines Symbols
Hydraulic system technicians always compare hydraulic lines and connections to the arteries and veins in your body. This is because these accessories are responsible for channeling your system’s hydraulic fluid throughout your system. These connections and lines are often depicted in hydraulic schematics using unique symbols such as:
This solid line depicts your hydraulic fluid’s flow path as it maneuvers through your hydraulic pumps, connections, and actuators.
This is simply a dashed line that represents the specific amount of hydraulic fluid designated to run one or several components of your hydraulic system.
This symbol features two crossing lines and it implies that the hydraulic fluid between two components or connections does not meet.
Although this symbol looks similar to the pilot line, it is visibly smaller. The drain line symbol represents the flow of your used hydraulic fluid as it is channeled back to your reservoir.
This symbol features several lines intersecting at a point, which is marked by a solid circle or dot. This symbolizes the connection point, where your hydraulic fluid is transferred to the other converging connections or lines.
This symbol features a curved line marked with solid dots at both ends. It represents flexible hoses in your hydraulic system. The marked dots on both ends represent possible attachment points.
The fast coupling symbol features a central solid line, which depicts your fluid’s flow direction. This symbol represents hydraulic connections and lines that you will find easier to assemble and disassemble.
How to Interpret Hydraulic Symbols
Hydraulic symbols may seem cryptic, especially when you are not familiar with them. However, with the right guide, you can unlock their true meaning. Beneath, we guide you through the basics of these symbols and how to interpret them.
- Continuous Lines:Continuous solid lines generally indicate the flow direction of your hydraulic fluid.
- Dotted Lines: Dotted lines in a hydraulic schematic simply refer to pilot signals. However, they are also often utilized to indicate drain flow.
- Circles: Circles are typically exploited to mark hydraulic rotary components. This could be your hydraulic motor or pump. Circles representing your hydraulic motor will feature an inward-facing arrow while those representing your hydraulic pump will feature an outward-facing arrow.
- Dash-Dot Lines: These dotted lines primarily represent the housing covering a myriad of your hydraulic components.
- Saw Tooth: This symbol generally represents the incorporated springs.
- Diamonds: The presence of a diamond symbol in a hydraulic schematic could stand for conditioning gadgets such as heaters and filters.
The Significance of Understanding Hydraulic Symbols
Without hydraulic symbols, illustrating the configuration of your hydraulic system would be a nightmare. Once you understand these pivotal symbols, they stop being a combination of lines and shapes. Here is why you should prioritize familiarizing yourself with hydraulic symbols;
- Boosts Your Understanding of Hydraulic Systems: Learning to deconstruct hydraulic schematics helps you understand your hydraulic system better. With this knowledge, you can maximize its output.
- Helps You Communicate Effectively: Once you are aware of hydraulic symbols, you can communicate with your hydraulic system technician more effectively. For instance, you can highlight issues with the system design.
- Troubleshooting: Hydraulic symbols summarize the distinct components in your hydraulic system. Learning to interpret a hydraulic schematic can be the key to identifying the root cause of a certain problem in advance.
- Safety: Imagine what could go wrong once you misinterpret a symbol and end up setting up your hydraulic system wrongfully. With this information, you can avert unprecedented accidents.
- Compliance: Industry standards demand that your hydraulic system should be operated or maintained by an expert. Learning the right symbols qualifies you to operate a hydraulic system.
Conclusion
These are some of the most common hydraulic symbols. In most cases, the hydraulic systems manufacturer will indicate the meaning of various symbols in their technical drawing.
In case you have any questions on hydraulic systems, TARGET HYDRAULICS team is always here to help – contact us now.
