Seal rings fixed

Fig. 4.6.8. (Right) Example of the fixed column end fitting for glass columns, suitable for water and organic solvents (after Ref. 18). 1, inlet capillary 2, thrust screw 3, seal made of soft polytetrafluoroeth-ylene 4, end fitting body made of plastics or metal 5, polyamide or polytetrafluoroethylene filter 6, cap nut 7, seal ring made of polytetrafluoroethylene powder or powdered mixture of graphite and polytetrafluoroethylene 8, rubber rings 9, column.

FIGURE 1.56 Sealing of the cavity for applying vacuum before injecting On the left Ejector half with peripheral sealing ring On the right Fixed half with vacuum connection above the cavity [15]... 

For the larger sizes in high-pressure service, the fixed-ball type with O-ring seat seals requires less operating effort. However, these require two different plastic materi s with resistance to the fluid and its temperature. Like plug cocks, ball valves may be either restricted-port or full-port, but the ports are always round and pressure drop is low. 

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