BELLOWS GRAFLEX SEAL FOR VALVE STEM WITH DRY SLIDING FRICTION Russian patent published in 2015 - IPC F16J15/18 

FIELD: machine building.

SUBSTANCE: bellows graflex seal for a valve stem comprises a fixed cover for a valve neck, a movable stem, a thrust ring, a bottom box with a press stud with nuts, a sealing ring from graflex, a ring preceding the gland and a bellows. One end of the bellows is tightly welded to the movable pre-gland ring and the other end - to the fixed cover. Due to the action of the compressed medium pressure the bellows moves the pre-gland ring, presses the sealing rings to the surfaces being sealed, seals the stem with dry sliding friction.

EFFECT: invention provides for the operation of a stem seal with dry sliding friction which prevents erosive wear of the stem surface and improves the valve reliability.

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