In the world of hazardous materials, evacuating them from their primary (and secondary) containment system plays a KEY role in performing maintenance/servicing on the system SAFELY. For example, opening a process/system that contains hazardous materials FIRST has to be evacuated of that hazardous material, and this evacuation to a “safe place” should be done through a Manual “Spring-Loaded-CLOSED” valve (e.g., a deadman valve). And this valve just may save a life?