Fire-resistant gate valve
 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. 
FMC Corporation
F F F Y
F16K F16K F16K Y10T
inventional inventional inventional additional
Alfred P. John N. Michael R. Ronald L. Stephen P. Bashir M. Kendall E. Charles E.
Regitz McIntyre Williams Riess Barrett Koleilat Keene Jennings