摘要 |
A ball valve or any other type of valve in which sealing surface of the seat ring and surface of closure member keep relative sliding contact during opening and closing movement of the valves. One or more annular grooves cut into sealing surface of the seat ring around it's bore are filled with lubricant or grease used for lubricating the surfaces so as to avoid or mitigate their abrasive wear or galling caused by frictional heat.
|