Due to its flow-promoting properties, the butterfly valve is used particularly for applications involving medium to large nominal widths. This is also due to the fact that the butterfly valve can be produced economically requiring a minimum of material and labor. An important motivation for the use of butterfly valves in applications involving large nominal widths is that in its fully open state, the pressure loss incurred due to geometrical factors remains extremely low. This means that no additional output is required by the medium delivery system. The flow pattern of the medium is extremely favorable within a completely open butterfly valve. In a partially opened status, a breakaway current occurs behind the valve, leading to turbulence. Even a streamlined disc can only conditionally settle the volumetric flow.
In conclusion, we may say that the butterfly valve is particularly suited for pure open/close applications involving clean, fluid and gaseous media and low switching frequencies.
A butterfly valve is only conditionally suitable for control of volumetric flow over the entire range from completely closed to completely open. The control characteristic curve does not indicate continuous control properties. Instead, the characteristic curve demonstrates several differing “control responses” overall.