Safety diaphragm

Outlets provided in the generator case for hot gas flow, igniter, pressure measurement, and safety diaphragm. 

Fio. 14r3. Safety diaphragm (frangible disk) for the relief of excessive autoclave pressures (a) Before bursting and (h) After bursting. 

N. A. Weil, Rupture Characteristics of Safety Diaphragms, J. Appl. Phys., 30 621-624 (1959). 

Tlie cover assembly usually contains a safety v ent. Tlie most common type consists of a steel or nickel diaphragm built into the cov er and a bent point cut from the cov er. At a certain internal cell pressure, the diaphragm niov es to the bent point and is pierced. Some cylindrical sealed cells use one or more temiinal feed-throughs employing glass-to-metal or ceramic-to-metal techniques. 

Users are warned that an ordinary spring loaded safety relief valve will not open at its set pressure if back pressure builds up in the space between the valve and rupture disk. A specially designed valve is required, such as a diaphragm valve or a valve equipped with a bellows above the disk. 

Doubie-waii cooied diaphragms reduce horsepower, aiiow higher compression ratios, maximum safety, avoid gas contamination, and ensure accurate process temperature controi. No water connections are between haives. These are not used for aii appiica-tions. 

Other elements especially designed to ensure a high efficiency and operational safety are devices that use bellow valves and diaphragm pumps that do not have primary moving parts in contact with the culture medium. More details regarding these and other devices are available in the technical literature (Krahe, 2003). 

Warning Never connect a gas cylinder directly to a closed system that is not specially designed to withstand high pressures (such as a combustion bomb for heats of combustion). Even when a regulator is used, remember that the diaphragm valve may slowly leak arrange for some kind of safety pressure release, if only a rubber tubing connection that can be easily blown off. 

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