US Patent 7506858 Tube-end butterfly metering and shutoff valve

A butterfly valve comprising a valve body having a passage, a valve shaft assembly, a plate, and a tube is provided. The valve shaft assembly comprises first and second shaft portions in opposing spaced relation, an intermediate portion therebetween, and a support plate secured to the valve shaft assembly. The first and second shaft portions rotatably couple the valve shaft assembly to the valve body. The intermediate member forms a chamber in fluidic communication with the passage. The support plate is disposed within the chamber at a closed valve position approximately perpendicular to a direction of fluid flow through the passage. The plate is secured to the support plate and has an inner portion and a flange radially outward of the inner portion. The flange is directed away from the support plate. The tube is disposed within the passage and friction or clearance fit over a portion of the flange.