Hydraulic directional control valves (DCVs), also sometimes called swtiching valves are an essential component across most hydraulic systems and many industries including construction, transport and agriculture.
This article will explain exactly what hydraulic control valves are, how they work, where they are found and detail some of the different types of DCVs and their key features.
What Are Hydraulic Directional Control Valves?
As the name suggests, a directional control valve in a hydraulic system controls the directional flow of the hydraulic fluid through the system. They also allow or prevent the flow of hydraulic oil or other fluids. So, not only can they control the flow direction but the flow rate, pressure and volume too.
Functionality of Hydraulic Directional Control Valves
Some of the main types of directional valves and how they work include:
- Check valves or non-return valves stop the flow of hydraulic fluid (or other liquid) one way and allow the flow the opposite way.
- Poppet valves are often piston or mushroom-shaped valves that seal or open to control the flow of hydraulic fluid.
- Directional spool valves are cylinders housed within an outer case. They move around either opening or closing the ports, or holes, within the case thereby controlling the flow of the hydraulic fluid.
- Solenoid valves are automatic electrical valves formed of an electrical coil wound around a magnetic core.
Applications and Importance
Directional valves in a hydraulic system can control the flow, volume, direction and pressure precisely.
Accuracy is key in many applications across many industries but one example is that of the landing gear on aircraft. Another is the gates on ships. Precision and reliability in these and many other other examples equals safety as well as efficiency.
Choosing the right valve for each specific application, operation and situation is of paramount importance for optimum efficiency and safety.
Key Features and Considerations
Some of the most important features and considerations include:
- The actuation methods; whether it is manually operated, mechanically operated devices or electrical/automatic actuation.
- The number of fluid ports required.
- The number of positions or directions required.
It is useful to know that DCVs are identified and classified using 2 numbers which explain the features mentioned above. The first number indicates the number of ports and the second number indicates the number of positions. For example, a 3/2 has 3 ports and 2 positions and a 2/2 has 2 ports and 2 positions.
Conclusion
Directional control valves enable hydraulic systems to operate smoothly, effectively, safely and in a timely manner. Shifting position at the right moment, and returning to their standby or default position so they are ready to go, like the superheroes of the hydraulic world.
Ensuring the right DCV is in the right place and is compatible with the hydraulic system is essential so it’s wise to get support and advice from a hydraulic engineer when selecting replacements.
If you have further questions or require one of our qualified and experienced engineers to keep your hydraulic systems in tip-top condition, get in touch with us at MCH Hydraulics today.