Emergency shut-down stations

No control system beyond a start-stop switch on the dispenser for the transfer pump is needed. An emergency shut-down switch should be installed at a location remote from the dispenser that will shut down all the electricity to the dispensing station. 

There must be a master control valve or switch accessible to and within 15 feet of the instructor s station for emergency cut-off of all gas cocks, compressed air valves, water, or electrical services accessible to students. Valves must completely shut-off with a one-quarter turn. This master control is in addition to the regular main gas supply cut-off, and the main supply cut-off must be shut down upon activation of the fire alarm system. 

Evacuation Plans. Many emergency events require the evacuation of at least some facility personnel, if only for precautionary reasons. This presents other needs, which must be addressed in the evacuation plan. Personnel who are directed to evacuate their normal work stations need visible wind direction indicators to help them move away from a dangerous gas cloud drifting downwind of the release point. If the building is enveloped in the cloud, however, they will need personal protective equipment in order to evacuate the building safely. When there are processes that must be rapidly shut down and/or isolated as evacuation proceeds, the plan must include written procedures and appropriate means to ensure incident-free action. 

Infra-red light curtains at the stripper loading station and stacking conveyor discharge points shut down the operation of the machine triggered by an operator. Pull-switches and emergency stop pushbuttons located at strategic points perform the same task manually. 

Emergencies are often discovered by personnel working in the facility, not by the trained responders. To minimize hazards and shorten reaction time to emergency situations, emergency evacuation pull stations are located throughout the facility. Triggering these alarms shuts down hazardous gas inputs into the building and announces an evacuation. 

The recirculating air stream is considered an integral portion of the life safety system therefore, in a hazardous occupancy cleanroom (such as a semiconductor wafer fab), the system should not be automatically shut down by the smoke detection system. In lieu of automatic shutdown, a manually operated remote switch is to be provided at an approved location outside the fabrication area (UBC 1202.2.5). Since such a detection could happen at any time, our recommendation for the location of the switch is in a continually occupied but relatively secure spot, such as the nearest Emergency Control Station (ECS). UBC 1202.2.5 also dictates that the return air system of one hazardous cleanroom area shall not be connected to another eleamoom oeeupancy. 

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