Valves are part of nearly every system and process, regulating the flow of liquids and gases. Valves are found everywhere—buildings and offices, hospitals and factories. Even with their ubiquity, choosing the right valve for a specific application might be more than it seems.
How to Choose the Proper Valve
Choosing the proper valve is a function of the level of system performance that you require. With this resource, we'll guide you through the key things to take into consideration in choosing the right one.
1. Be Cautious When Choosing the Valve Size and Type
Valves come in many different sizes and types, and each is designed to be used in a specific function—pressure relieving, shutting off flow, backflow prevention, diverting or mixing flow, or regulating flow. What the valve should be applied for will determine what type should be used.
Some of the most widely known types of valves include:
-
Shut-off valves
-
Pinch valves
-
Pressure regulators
-
Relief valves
-
Stopcocks
-
Toggle valves
-
Metering valves
-
Needle valves
-
Ball valves
-
Check valves
To make the right choice, align the valve’s type and size with the system’s specific functional needs.
2. Check for Special Valve Requirements
Before selecting a valve, ensure it meets your operational requirements.
Key factors include:
-
Actuation speed: How quickly does the valve need to open or close?
-
Energy consumption: How much power is required to operate it?
-
Default state: Is the valve normally open or normally closed?
Understanding these parameters guarantees the valve will perform best in your system. If a valve is open or closed under normal circumstances, it will impact reliability and system safety.
3. Consider the Materials of Construction
Valves must be chemically compatible with the materials they will be handling. Material selection is crucial:
Plastic valves typically possess excellent corrosion and abusive chemical resistance.
Metal valves will tend to work better with high pressure and high temperature service.
Choose materials suitable not just for the strength but also for long-term compatibility with the gases or liquids in use.
4. Check Performance Specifications
Subject the pressure and temperature ratings of the system on which the valve is to be mounted for testing. For applications involving high temperatures or pressures, metal valves are the best option. Plastic valves, while ideal for some chemicals, cannot withstand very severe physical strain.
In pressurized gas applications, metal valves are typically the most robust and safest option.
5. Maintenance Planning
Maintenance is a necessary but often overlooked factor. Your valve selection should take into account how frequently the valve will need to be replaced or maintained.
As an example, ball valves resist clogging and mechanical failure well, making them well suited for low-maintenance systems. Ball valves are not well suited for flow regulation, though, since throttling produces premature wear or leaks.
Knowing the compromises between usability and utility ensures reliable long-term system performance.
6. Most Valuable Valve Types to Be Familiar With
Here's a brief description of three of the most popular valve types and how they work:
Solenoid Valve
Electrical solenoid valves contain a movable magnetic plunger and a coil. On the application of an electric current to the coil, the magnetic field lifts the plunger, allowing a passage for fluid or gas. The solenoid valves are well adapted to the on/off control of automated systems.
Pneumatic Valve (Directional Control Valve)
Pneumatic valves control compressed air flow within automation controls. They come in many forms depending on functionality, flow capacity, and form. Proper choice involves evaluating pressure range, actuation means, and overall system requirements.
Butterfly Valve
The butterfly valve is typically used to control the flow rate of fluids. It regulates water, oil, and mildly aggressive fluids like water, oil, and minor chemicals. But not for solids or fluids with particles because it can interfere with sealing.