When a fluid passes through the constrictive passageways of a control valve, its average velocity increases. This is predicted by…
The root cause of the problem – a varying pressure drop caused by frictional losses in the piping and other…
Control valves are mechanical devices with moving parts, and as such they are subject to friction, primarily between the valve…
Both gas and liquid control valves may experience what is generally known as choked flow. Simply put, “choked flow” is…
The flow capacity of a valve (Cv) is a quantitative rating of its ability to pass a fluid flow for…
Sizing a control valve for gas or vapor service is more complicated than for liquid service, due to the compressibility…
What is inherent characteristic of a valve ? The inherent characteristic of a valve is the characteristic published by the manufacturer,…
Now let us consider a scenario where the pressure drop across the valve changes as the rate of flow through…
First, let us imagine a control valve installed at the base of a dam, releasing water from the reservoir. Given…
The purpose of a valve positioner is to ensure the mechanical valve’s position matches the command signal at all times.…
