A valve assembly uses an O ring contained within a void such that the outer edges of the valve assembly reach the outer mid section of the O ring. A kettle for brewing beer or heating other fluid is drilled so as to accommodate the disclosed valve. The O ring is pressed and held against the outside surface of the kettle wall. A retaining nut placed within the kettle further secures the valve to the kettle. As the surface of the kettle heats during use, the contained O ring retains sufficient contact with the valve and kettle so as to prevent leakage.