Shut-off valve with bellows sealing - has two internal bellows, one softer than other, activated by shoulder on positioning rod

摘要

A shut-off valve with a siphon gland has a housing (3), a central positioning rod (1) and a shut-off element. Two concentric extendable bellow sleeves (6, 10) are sealed with each other via a cylindrical sleeve. The inner bellow is softer thant he outer bellow, and the flexible ends of both bellows and the cylindrical sleeve are fixed against rotation in the direction of bellows movement, in at least one position along the length. The positioning rod has a shoulder (5) which moves the cylindrical sleeve and acts as limit stop for the inner bellow. ADVANTAGE - Easy manufacture, assembly.