Valve vs. Regulator: What’s the Difference?

Valves and regulators are two pneumatic tools that every engineer, operator and other stakeholders should be aware of. Understanding the distinction between the two is important in the automation industry because, although they serve the same purpose of automated control, they have separate designs and operations.  

Turborevs highlights the major differences between a valve and a regulator below to help determine the most suitable choice for various applications. 

 

Differences Between a Valve and Regulator

Function

A valve relieves a system’s pressure levels beyond a predetermined set point value. It opens to release the building pressure, and closes once a more stable level has been achieved. The extent to which its position needs to deviate is communicated by a distributed control system (DCS) in the form of signals.

On the other hand, a regulator controls and maintains the pressure within an application by adapting the inlet pressure levels. It is reactive to the pressure of the liquid or gas, and changes accordingly. It first applies pressure of the process fluid against a diaphragm, which then opposes a compressed spring for balance at a given pressure. Any changes cause movement in the diaphragm, which in turn allows more or less flow of the process fluid through the regulator.

In other words, regulators are process-powered valves that do not require an external power or instrument air source. 

 

Speed of Response

 

 

As any top-quality regulator is quick to respond to any changes in the controlled pressure, as well as the fact that it does not rely on an intermediate system, its speed of response is faster than that of a control valve. In contrast, a valve is dependent on sensors, DCS and actuators — which subjects it to higher risk of operational failure if even one of these turn out to be defective. 

 

Pressure

Valves are usually available in larger sizes with higher pressure classes. The body of a regulator typically has a relatively low pressure rating, whereas control valves are designed to handle the same pressure on the output due to their compatible metallic trim materials and the fact that they are on the inlet side. Regulators, in general, will have at least one elastomeric material exposed to the process fluid, so they cannot be used in highly corrosive applications.

 

Cost

 

 

 

The total costs of installing and maintaining regulators are normally lower than those of inserting valves. However, it is important to remember that some site standards or project specifications may require a control valve for its control applications instead of a regulator. Hence, those should be taken in consideration as well rather than just choosing on the basis of the cost difference. 

 

Which Should You Choose?

Your selection may vary, depending on the application in question. For instance, a regulator may be the more appropriate choice in some cases as it does not require a supporting system to operate. However, a control valve may be more effective for predictive maintenance feedback or diagnostic monitoring as it can communicate data to an auxiliary control system. 

It is important to know the features, benefits and safety guidelines of both solutions as understanding the different capabilities of each can help you make the right decision, and avoid any future problems or waste of resources. Just take note to invest in high-quality valves and regulators (as well as other car tuning parts) for optimum performance.