What is the standard for a butterfly valve? The two most common connection methods for butterfly valves are wafer-style and flange-type. The difference between the wafer type butterfly valve and the flange type butterfly valve is not only the difference in the outer shape structure, but also the biggest difference is the installation. When a flanged butterfly valve is installed on a pipeline, because it carries two flanges, the flanges at both ends of the butterfly valve can be directly connected with the flanges at both ends of the pipeline and can be fixed by bolts; the installation of the wafer butterfly valve is relatively troublesome, because it does not have its own flange piece, and it must be equipped with a flange piece when it is installed on the pipe. It is necessary to weld the two flanges to the two ends of the butterfly valve respectively. Then the welded flange pieces and the flanges at both ends of the pipe are connected by double-headed bolts. It should be noted that the flange used for the installation of the wafer type butterfly valve is a butterfly valve special flange and has a corresponding flange standard.
Why do wafer butterfly valves require special flanges? What is the difference between a butterfly valve flange and an ordinary flange? The answer is the difference in the inner diameter of the flange. The inner diameter part of the special flange of the butterfly valve has an inner groove. When the special flange of the butterfly valve is connected with the inner diameter of the valve body of the butterfly valve, this inner groove can just be inserted inside the inner diameter of the valve body, ensuring the sealing effect of the flange connection. If an ordinary flange is used instead of the inner groove, the sealing performance at the flange joint cannot be guaranteed. In addition, studs are used for the bolts used to secure the butterfly flanges and pipe flanges.