Abstract: A stem-operated fire-resistant gate valve including an improved metal-to-metal stem backseat fusible ring assemblies for facilitating automatic stem backseating at pre-selected temperatures, spring enhancement of the backseating procedure, and an improved metal-to-metal gate seat.

Abstract: A fluid pressure seal comprising the combination of a metallic sleeve-like member having one or more annular grooves around its outer periphery and two or more annular grooves on its inner surface, the grooves located to establish an accordion-like area in the member intermediate its ends, and flexible non-metallic sealing material within and filling the grooves. When the seal is installed between two adjacent metallic surfaces, such as around a valve stem and within a chamber in a valve bonnet, axial compression of the seal causes radial expansion of the accordion-like area into fluid-tight contact with those surfaces to produce a metal-to-metal static and dynamic seal therebetween.