Choosing a Linear Proportional Valve
Selection of a linear proportional valve should be based on adaptation of technical characteristics of the valve to the entire operating system and not only by price or nominal size.
1. Definition of Fluid
It is necessary to define whether the valve will handle air, water, oil, gas, chemicals, etc. Compatibility of fluid, valve body, seals, and internal components.
2. Calculation of Required Flow
Minimum, average, and maximum flow requirements must be calculated. If the valve is too small, there will be a restriction in the system. On the contrary, large capacity makes it more difficult to accurately control low flow.
3. Checking Operating Pressure
Confirm minimum and maximum inlet, outlet, and differential pressures. The valve has to operate reliably throughout the entire expected pressure range.
4. Electrical Requirements Confirmation
Confirm supply voltage, current, signal type, connector, wiring,, and driver neeConfirmsure that the valve is compatible with the PLC or controller used in your equipment.
5. Estimation of Response and Accuracy
Fast automation, dosing, testing, and precision applications. Response time, repeatability, hysteresis, resolution, and proportional properties.
6. Check Temperature
Fluid temperature and ambient temperature must be taken into account. Suitable sealing and construction materials should be chosen considering the operating conditions.
7. Mechanical Installation Inspection
Port size, connection type, mounting dimensions, overall envelope, and available installation space must be checked.
8. Consideration of Control Integration
It should be defined if the application requires open-loop operation or the presence of sensor feedback. Compatibility of the valve with the controller, driver, and control software should be checked.
9. Assessment of Supplier Support
Samples, Customization, Technical Documentation, Testing, Quality Control, Lead Time, After-Sales Support
Final advice: make a complete specification sheet before buying. Test the selected valve in real operating conditions where it is possible.
Linear Proportional Valve Design: Avoiding Common Mistakes
Don’t size by pipe diameter alone. Calculate the required flow and pressure conditions.
Never forget about differential pressure. Performance of the valve depends upon the pressure differential across the valve.
Don’t select the electrical interface incorrectly. Verify voltage, current, signal type, connector, and driver requirements.
Media compatibility should not be ignored. Check valve body and seal materials with actual media.
Not all proportional valves have the same response. Compare response time, hysteresis, resolution, and repeatability.
Don’t forget about temperature. Take into account the temperature of the fluid and environment.
Don’t design without measuring the installation. Port size and clearance and port size and mounting holes must be measured.
Don’t forget about filtration. Fluid contaminants may affect internal moving components and control performance.
Prototype testing? Never skip this step. Test the valve under realistic pressure, flow, temperature, and duty-cycle conditions.
“Don’t just consider the purchase price. Consider reliability, maintenance, integration, energy use, and total cost of operation.
