Abstract

The self-draining sanitary control valve includes a body having an inlet and an outlet and a fluid control port forming a valve seat between the inlet and the outlet. A bonnet is detachably secured to the body having a stem receiving bore aligned on a common central axis with the control port. Clamping rings are provided for securably clamping the body and bonnet together and for securing the valve body to adjacent fluid lines. The clamping rings are readily detachable for permitting the valve to be cleaned and the interior surfaces of the valve are closed to provide for self-draining of the fluid contained therein. The valve includes a stem slidably mounted in the bore with a valve plug at one end having a predetermined outer surface profile movable toward and away from the port and a flexible diaphragm is secured to a central portion of the plug for engaging the valve seat. An outer portion of the diaphragm is clamped between the body and the bonnet when the clamp ring is locked in place. A central portion of the flexible diaphragm is permanently secured to the profiled outer surface of the valve plug to provide a matching profile similar to the valve plug for cooperation with the valve seat to result in a predetermined flow characteristic that is dependent on the profile of the valve plug rather than the resilient characteristics of the diaphragm alone.