Emergency Shutoffs

Fabrication Areas. A manual control switch must be provided which, when activated, will shut down exhaust ventilation and turn off all lights in the fab (H-6) area except those required to sufficiently illuminate means of egress. The Uniform Fire Code requires that the lighting be shut off if the exhaust is shut off (the rationale is that people will not re-enter a dark facility). 

Another manual control switch is required for shutting down the recirculating fans (which supply air to the HEPA/ULPA filter ceiling of the cleanroom) and shall be installed at an approved location outside the fabrication area. We recommend that one switch be provided for the makeup air and exhaust fans, with a separate switch for the recirculating HEPA fans. 

HPM Storage Rooms. A manual control station or shut off valve unique to HPM storage rooms is required. 

All emergency shutoff control stations should be mounted in some type of break-glass enclosure with the locations coordinated with the local fire chief They could be located at the emergency control station, if approved by the authority having jurisdiction.  

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Propagation Minimize Hazardous Materials, and Flammable Quantities, Maximize Use of Non-flammable, Equipment Spacing, and [nstail Check and Emergency Shutoffs. 

Propagation Diminish Emergency material transfer Reduce inventories of flammable materials Equipment spacing and layout Nonflammable construction materials Installation of check and emergency shutoff valves... 

Fire fighting equipment should be mounted at heights that are easily accessible by the average person. This includes portable fire extinguishers, hose connections to fire hydrants, access to emergency shutoff valves, emergency stop/ESD push buttons, etc. 

Does the transfer operation incorporate an emergency shutoff system ... 

TANK FILL CAP AND DROP TUBE ADAPTER 0 TANK DROP TUBE 0 SUBMERGED TRANSFER PUMP 0 PIPELINE LEAK DETECTOR 0 EMERGENCY SHUTOFF VALVE 0 SWING JOINT AT A CHANGE OF DIRECTION 0 EXTRACTOR ASSEMBLY [Pg.94]

Careful design of guards is vital. An ineffective guard can be worse than none at all, as it can give rise to a false sense of security. Emergency shutoff devices may be needed, in addition to electrical and mechanical guarding. 

Safety assurance in the design of the HTTR steam reforming system against fire or explosion of flammable product gas mixtures is the task of the secondary helium piping system which is designed to limit gas ingress by means of a combination of containment vessel isolation valves and emergency shutoff valve in the process gas feed line [33]. 

Multiple Operators Ifthere is more than one operator for a machine, each should have a separate set of controls. Each set of controls must link to all other sets. All operators must have their hands free of the point-of-operation before the machine can start its motion. In addition, when there are multiple operators, each should have an emergency shutoff within reach from their work position. 

Escalators have emergency shutoff switches at each end. They have microswitches located at various points along and behind the side wall panels to stop the escalator if something gets caught between the steps and the sidewalls. 

The different methods of unloading may require different valve types and related equipment. In all cases, the liquid unloading line should be equipped with a pressure gauge and shutoff valve. As mentioned earlier, the unloading lines should be equipped with properly sized excess flow valves or emergency shutoff valves to protect against loss of product in the event of a hose failure. 

Many vendors now sell gas cabinets equipped with self-closing and latching doors and windows, sprinkler heads and various types of purge assemblies (see Fig. 5). Cabinets should be provided with a minimum flow of 100 feet per minute through the louver on the cabinet bottom. When the window is opened, the face velocity through the window should be maintained at 100 fpm. Purge assembhes may contain many different types of safety devices. An emergency shutoff valve should be located as close to the cylinder as is practicable. An air operated remotely activated cylinder valve is more preferable. System shutoff may be by manual activation of a remote switch in the laboratory or fabrication area or caused by other system defaults interlocked to gas flow. System defaults may include ... 

Emergency shutoff valve. This valve is usually automatic and will shut off the cylinder source when tripped. 

There are a number of automatic monitors available that combine a number of the functions mentioned above into a single unit. These are sometimes connected to the panel s emergency shutoff valve or plant alarm systems, and will usually allow the operator to shut off the cabinet/panel by depressing an emergency shutoff button. For more extensive system control, the automatic gas cabinet controller, explained in the next section, should be used. 

The functions of emergency stop of an engine, of access management, or of ESV (emergency shutoff valve) are intended to ensure the safety of the system in the presence of danger and, therefore, are crucial to prevent damage to goods and people. Risk analysis is used to indicate the safety level that can be achieved. 

Common controls. All workers handling or using cylinders must have basic training in the use of gas cylinders, emergency shutoffs, proper equipment design, leak-testing procedures, and the use of appropriate respiratory protection in the event of a release of a compressed gas. Other controls include the following ... 

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