A butterfly valve comprises a housing including a bore, a rotatable shaft passing through the bore, a disc mounted to the shaft for controlling the flow of a fluid through the bore, a thrust load reacting section and a wear interface. The thrust load reacting section includes a thrust plug assembled in a thrust reacting end of the shaft and a thrust plate secured to the housing. The thrust plate has a well for axially retaining the thrust plug and the thrust reacting end of the shaft. The wear interface includes a first contact region on the thrust plug with a first contact surface and a second contact region at the base of the well with a second contact surface. A portion of the first contact surface is spherical and in contact with a portion of the second contact surface.