www.safetyandhealthmagazine.com/articles/pneumatic-valve-2

Pneumatic valve

June 1, 2011
The Pneumatic Valve+ allows the configuration of an array of valves, trapped key interlocks and key switches in any combination. It is suitable for the isolation of a pneumatic power source and is conventionally key-free, but can be used in conjunction with other functional modules. With the PV+, a combination of isolation/access keys is possible, with sequential or non-sequential key operation available.

Fortress Interlocks Ltd.