The flow coefficient of a control valve (Cv) is a numerical value expressing the number of gallons per minute flow…
When control valves operate between fully open and fully shut, they serve much the same purpose in process systems as…
In Control Valve Sequencing, for example, both control valves received the same pneumatic signal from a common I/P (current-to-pressure) converter.…
Another form of control valve sequencing is used to expand the operating range of flow control for some fluid beyond…
Other applications for split-ranged control valves call for a form of valve sequencing where both valves are fully closed at…
The first type of control valve sequencing is a mode where two valves serve to proportion a mixture of two…
The reason why a pneumatic control valve’s stem position corresponds linearly to the amount of air pressure applied to the…
In some process applications, it is important that the control valve be able to completely stop fluid flow when placed…
A completely different approach to packing is a device called a bellows seal : an accordion-like metal tube fastened to…
Regardless of valve type, all stem-actuated control valves require some form of seal allowing motion of the stem from some…
