AVR shut-off valves with stem-sealing screwed-in bush and AVB shut-off valves with stem-sealing metal bellows.
Operated by a handwheel or a ratchet: AVB & AVR shut-off valves. Closed off clockwise and opened counter-clockwise, the valves include a back seal. When the valve is open fully, the screw bush and seal can be replaced. AVB shut-off valves are fitted with metal bellows to ensure a complete hermetic sealing.