Abstract: A butterfly valve comprising a valve body, a throttle plate located within a throat of the valve body, and opposed projecting pins connected to the throttle plate and extending into two opposed bores of the valve body. At least one pin has an annular bearing surface. A spring urges either a thrust bearing against a needle bearing which in turn bears against the annular bearing surface or a needle bearing against the thrust bearing to bear against the annular bearing surface. This urges the throttle plate against an opposed thrust bearing which bears against the opposed projecting pin connected to the throttle plate to center the throttle plate within the throat of the valve body. A set screw can be provided to accurately position the throttle plate within the throat of the valve body. Preferably the throttle plate has tapered end sections to diminish turbulence within the valve throat.