| 摘要 |
A lined butterfly valve for use in controlling the vacuum in a vacuum processing chamber includes one or more liners (70, 86) which can be easily changed out to control contamination particulate buildup in the processing chamber and closely adjacent vacuum system piping. A removable flapper disk (180) is attached to a stem portion (104) of a stem shaft which is supported by an easily removable valve stem bearing and seal cartridge assembly (100). The valve stem bearing and seal cartridge assembly (100) is keyed to and clamped to the outside of the valve body by an easily releasable clamping plate. A set of valve seating lips (76, 90) in the liner prevent excessive gaps between the flapper disk and the liner and also provide structural support to prevent the valve flapper from bending under severe pressure conditions. The connection between the valve flapper disk and the valve stem is accomplished by a captured screw assembly (210), which prevents the attachment screw between the flapper disk and the stem from being separated from the flapper disk during the disk's removal and re-installation. This arrangement reduces the mean time to recover from a cleaning cycle of the processing chamber. |
