Butterfly Valves - the cheap plain-vanilla Process Control Valve?

摘要

Every engineer in the world knows about butterfly valves and especially the Wafer/Lug type versions. The butterfly valve is quite a young process control valve which was developed at the end of the 19th century, mainly for use in Hydro Power Stations as an inflow securing system - and what a wonder the double eccentric/double off-set butterfly valve is in regard to the usual high working pressure/differential pressure.