Butterfly valves are aptly named for the mechanical movement of the inner workings of the valve. They control the flow of material through a circular pipe or tube by the use of a disc that pivots, often looking like the wings on a butterfly as it moves back and forth to regulate the flow.It has a rotating disc that controls water flow. Some models have a lever handle to control the disc's position inside the valves; rotating the handle counterclockwise closes the disc. Other versions include worm gear to work the disc; twisting the worm gear clockwise opens the disc. Installing wafer butterfly valve is moderately difficult. It is also available in a variety of styles and pressure ratings. They install within the pipe or tube between sections and are controlled by turning the actuator that is housed on the top of the valve itself.
When people install it, first of all, clean the equipment carefully, making sure any debris, dust, oil or other material is not in the way on the valve, flanges, gaskets or pipeline. Remove all other contaminants from both pipe flanges by rubbing them with sandpaper. Open the valve and clean the sealing edge of the disc. Each pipe flange contains a series of bolt holes.
Then close the valve so that it is installed in this position. Install the flanges or collars on either side of the section of pipeline on which the butterfly valve is being installed. Flanges or collars create a seal and a place to attach the valve to the smooth ends of the pipeline. The type will depend on the type of valve you are installing. The flanges or collars mount on the ends of the pipeline and are tightened down, using tension to seal the connection.
Thirdly, slip the valve between the flanges or collars on the pipeline, making sure not to scratch the gasket sealing surfaces on the valve or flanges. Make sure the bolts and holes are centered and mated before tightening the bolts completely. Tighten the bolts evenly in a crisscross pattern to apply even tension. Moreover open the valve slowly to check for adequate clearance within the pipeline until you are sure it is operational.