Abstract

A mud valve having a flange frame and yoke that are permanently connected to form a single unit without the aid of removable fasteners is described. Installation of the drain plug is facilitated by an arrangement of guide tabs on either side of the drain plug that are of different distances from the surface of the drain plug. This staggered arrangement allows the drain plug to be installed through a tilting and rotating of the drain plug that brings the tabs into alignment with guide rails on the yoke without necessitating the separation of the yoke from the flange frame. Similarly, the construction described allows the drain plug to be removed for repair or replacement in the field without disassembling the yoke and flange frame.