Its function is the same as an ordinary butterfly valve. Through Procedure, it is actually clamped amongst the flanges with screws. For servicing, the screws are loosened. The valve portion can then be pulled out for straightforward servicing. This kind of valve is useful for automated control of pressures, flows http://reidvdkta.articlesblogger.com/11137681/the-fact-about-valves-and-fittings-that-no-one-is-suggesting