Hydraulic Valves: Control Point of Fluid Power
Hydraulic Valves: Control Point of Fluid Power
Hydraulic Valves: Control Point of Fluid Power
Hydraulic systems are one of the most critical energy conversion tools in today's industry. Hydraulic valves, which are considered the heart of these systems, have decisive functions in terms of safety, efficiency and accuracy of the system, beyond being just mechanical parts. In this article, we will discuss what hydraulic valves are, how they work, and why they are so important in technical and understandable language.
What is a Hydraulic Valve?
To put it simply; A hydraulic valve is a control element that directs the flow of fluid (usually hydraulic oil) in the system and controls its flow and pressure. It works kind of like the traffic light of the system; It determines when to go with the flow, where to change direction, and at what speed it should proceed.
Hydraulic Valve Types and Their Functions
Hydraulic valves are divided into different categories according to their functions. Each type responds to a different need of the system:
- Directional Control Valves: By determining the direction of the fluid, it provides movements of actuators (for example, cylinders) such as forward-backward or up-down.
- Pressure Control Valves: By preventing the pressure in the system from exceeding a certain level, it both ensures safety and extends equipment life.
- Flow Control Valves: It controls the speed of movement by adjusting the speed of the fluid, that is, its flow rate.
- Proportional and Servo Valves: It is used in automation systems where precise and continuous control is required. They work with electronic signals and offer millimetric control.
Working Principle: Pressure-Directing Technology
The working logic of hydraulic valves is basically based on the orientation of the fluid according to pressure differences. When a valve is opened, the fluid travels in a certain direction. If it closes, it stops or is diverted to another channel. This control is often achieved mechanically, sometimes by electrical, electromagnetic or proportional control.
Uses: Unseen Heroes
Hydraulic valves have a much wider range of uses than one might think. Today, whether it's a crane operator, a bucket user, a robot on a production line or an airplane's landing gear system, one or more hydraulic valves play an active role. The main uses are:
- Construction machinery and agricultural equipment
- Industrial automation systems
- Hydraulic press and die machines
- Mobile hydraulic systems (e.g. van-mounted cranes)
- Defense and aerospace applications
The Importance of Choosing the Right Valve
The most critical factors to be considered in hydraulic valve selection are; system pressure, flow requirement, environmental conditions and control sensitivity. Choosing the wrong valve can lead not only to loss of performance, but also to serious equipment failures and safety risks.
Maintenance and Signs of Failure: Silent Warnings
Valves usually operate quietly; However, if there are symptoms such as slowdowns in the system, temperature increases, vibrations or unwanted noises, this may be a sign of failure. Periodic maintenance, keeping the filters clean and checking the quality of the oil; It ensures long-lasting and safe operation of the valves.
Conclusion: Valves are not just parts, they are the mental center of the system
Hydraulic valves determine not only the direction of a system, but also its behavior and balance. Without them, a hydraulic system either works inefficiently or does not work at all. For this reason, an engineer or technician should consider valves not only as a fastener; They should see them as decision-making brains.
Real-Life and Industrial Examples of Hydraulic Valve Use
- Use of Directional Control Valve in Excavators
Scenario: An excavator operator moves the joystick when he wants to lift the lever or open the bucket.
Valve Role: Joystick signal triggers the directional control valve. This valve ensures that fluid flows into the correct hydraulic cylinder.
Result: The lever is raised or the bucket is opened. If the valve does not work, the system does not move or moves in the wrong direction.
Warning: A defective directional control valve can cause the bucket to fall and lead to serious occupational accidents.
- Use of Pressure Control Valve in Hydraulic Presses
Scenario: An automotive factory uses a hydraulic press machine that cuts sheet metal.
Valve Role: The pressure limiting valve limits the maximum pressure applied to the cylinder.
Result: The pressing process takes place smoothly and safely. Otherwise, excessive pressure will cause damage to the molds.
Warning: An improperly adjusted pressure valve can put operator safety at risk and cause permanent damage to the equipment.
- Use of Flow Control Valve in Mobile Cranes
Scenario: A boom crane operator wants to lift a person from a height to the top at constant speed.
Valve Role: The flow control valve regulates the lifting speed.
Result: The platform rises at a balanced and constant pace. Without flow control, the speed will be uncontrolled and occupational safety will be compromised.
Tip: Flow control valves should generally be selected to operate stably even under variable load.
- Use of Proportional Valves in Industrial Robots
Scenario: A robot on a production line performs a precise assembly operation (e.g., electronic circuit insertion).
Valve Role: The proportional valve controls the hydraulic flow millimetrically according to electrical signals.
Result: The robot arm moves at a certain speed, with a precise force. This is only possible thanks to proportional valves.
Note: These systems require PLC or controller integration along with the valve.
- Use of Combination Valves in Agricultural Equipment
Scenario: The rear equipment of a tractor (e.g. a plow) must be both lifted and tilt adjusted.
Valve Role: The combination valve system provides both direction and pressure control at the same time.
The result: The equipment is both lifted up and fixed at the right angle in a controlled manner.
Advantage: Multifunctional valves are preferred in agricultural machinery to save space and cost.
- Safety Valves in Aviation
Scenario: Consider a hydraulic system that works to deploy the aircraft landing gear.
Valve Role: The safety valve protects the hydraulic circuit by preventing pressure increase in the system.
Result: Flight safety is ensured. Otherwise, the system may malfunction and the tools may not be able to open.
Note: This article has been prepared by Hidroman's technical consultancy unit. For more information, you can contact our expert team or visit our product pages.