A lightweight butterfly valve having a disk maintained in a fixed position on a compound shaft through an interlocking relation ship between each of the individual shafts of the compound shaft and the disk as the disk is moveable between an open or closed position with the butterfly valve may having other features such as an electric drive to quickly rotate the compound shaft to provide for rapid opening and closing the butterfly valve, a disk position indicator and a shaft stop to prevent the disk from being driven past a full open condition.