RETAINER LOCK NUT FOR THE STEM PACKING OF A FLUID PRESSURE CONTROL DEVICE

摘要

A control valve includes a valve body (14) defining a top opening. A bonnet (28) is provided for closing off the top opening of the valve body. A stem (40) housed in the bonnet and the valve housing slidably moves a valve plug (30) in the valve housing to open and close the valve. A packing assembly (44) is provided for sealing between the stem and bonnet, and a packing retainer maintains the packing assembly within the bonnet. A retainer ring (12) is provided for securing the packing retainer (48) in place. The retainer ring can be formed as a generally cylindrical ring that engages the packing retainer and can be tightened on the packing retainer. Outer notches (56) formed in an exterior surface of the lock nut provide for tightening of the lock nut with a tool. In addition, the retainer ring may include a lower portion that closely receives an outer surface of the packing retainer, thereby to center the retainer ring with the packing retainer. Still further, the retainer ring may have an upper portion that automatically centers the retainer ring with the bonnet.