When it comes to selecting the right type of Pneumatic Control Valve for any application, you have many options at your disposal. Each comes with its own specific function, so it is helpful to understand differences and pick the type best-suited for your requirements.
To help you arrive at the valve “type” that’s right for your pneumatic application, this post will highlight five basic requirements to consider:
The first and most obvious question is—what gas (or liquid) will be controlled by this pneumatic control valve, and at what input pressure? Compressed Air? Water? Negative Pressure? Gas? Before checking for any additional factors, ensure that the valve is compatible with the media and pressure passing through.
There are a variety of methods available to open or close a pneumatic control valve. The four most common methods of valve actuation are:
This is the return method the pneumatic valve will take “back” to its original, un-actuated state. Typically, this is either a mechanical spring, or a separate form of the same actuation method described above. Manufacturers call these methods “spring return” and “detented” valve types. Said another way, are you looking for a “momentary contact, momentary output” or “momentary contact, maintained output”? Decide whether you want your valve to return to its initial position or stay in its last position after actuation.
Most pneumatic control valves are 2-Way, 3-Way or 4-Way and, as a rule of thumb, it is a count of their active media ports:
Note: As an option, 4-Way valves can be configured with 3 positions, where the center position is forms a “neutral” position choice of three options (either all OUTLET ports exhausted, pressurized, or checked).
Flow capacity is a fifth factor to address in pneumatic control valve selection. An undersized valve will slow down fill time or cause other forms of inefficiency in the system while an oversized valve can be classified as a form of waste in the system. It’s important to estimate a maximum flow capacity for your application and select the valve size with enough capacity. All valve suppliers provide a flow capacity, and have easy reference material to assist you, but essentially your valve will need to fill a specific downstream volume within your acceptable period of time.
Tip: Most manufacturers state a “Cv” value, which is a universally accepted flow capacity index, known as “flow coefficient”. It forms an easy way for you to compare similar sized valves.
Once you’ve used these five factors to identify the valve type you need, then weigh specific performance and integration attributes of matching brands and models available from valve manufacturers. Still a bit overwhelmed? Don’t worry! We’ve made it easy to browse our online catalog and narrow your results until you have found the exact products needed for your specific application. You can even search within results for the exact terms you’re looking for.
If you’d like more help choosing the right pneumatic control valve, or have questions about any of our products, please contact us at 1-800-477-8707.