Pneumatic Control Cabinet

grabcad

I had a safety critical control application, could of done it with a battery backup and a PLC, but decided to challenge myself and do it old school like I used to as a job pneumatically. Rules were. 1.Air failure, extend actuator & lock. 2 Pressure differential detected, extend & lock actuator. 3. Power failure, extend actuator, no need to lock. 4. If Air or Pressure diff extends actuator, it can not be commanded open until triggers are resolved. Issue discovered, forgot to put output lines out of the cabinet. Discovered this when i went to rfex it into the device & plumb it up.