Definition While many control valves throttle in mid-travel positions throughout their operating lives, some applications include a requirement for the control valve to stop, or…

Sliding-Stem – For sliding-stem valves, the ratio of the maximum to the minimum usable Cv is highly variable, but is generally between 20:1 and 100:1.…

Control valve rangeability is a specification that is closely associated with the concept of flow characterization. Unfortunately, the term rangeability is often misused. Definitions Classical…

While a thorough dynamic analysis of the system can be performed to guide the selection of a particular valve characteristic, the use of established rules…

Selecting A Characteristic – To provide linear system gain over the entire operating range of the system, an equal percentage valve characteristic is selected. This…

Typical Pump And Piping System – The objective of flow characterization is to select a valve gain curve that will match with, or compensate for,…