Abstract: A metal valve stem is attached to a ceramic valve plug. An elongated metal screw member has an expandable section securely wedged into a cavity in the plug as the attached screw/ceramic plug are threadably tightened on the valve stem. A first pre-wedging step presses an expander on the screw to fully bend the expander inside the ceramic cavity. The second wedging step during tightening of the screw/plug on the stem ensures uniform loading of the expander on the ceramic cavity surfaces.

Abstract: A separable flange retainment system includes a first boss on the flange and a mating second boss on a valve body. The boss on the valve body has a threaded aperture for reception of a suitable fastener. A generally U shaped retainer device having an orifice in its bight portion straddles the bosses and is secured in position by the fastener. The retainer device precludes lateral and rotational movement between the flange and the body.

Abstract: A valve assembly includes a bonnet that is captivated in a valve body stem mount by means of a threaded bonnet nut. A pair of opposed pry holes are formed in the bonnet at a point above the top of the fully seated bonnet nut. Loosening of the bonnet nut enables a bonnet that is stuck in the body stem mount to be pried loose with a pry bar inserted in one or both of the pry holes and levered against the top of the bonnet nut. The bonnet holes also provide a visual indication of movement of the bonnet and whether there is pressure in the valve body.