Procedures gas handling

Many physical chemistry experiments involve the use of one or more gases such as oxygen, nitrogen, hydrogen, helium, argon, and carbon dioxide. We shall be concerned here with procedures for handling these gases. 

Cylinders, Gas Regulators, Reducing Valves. Although some gases can be prepared in chemical generators, see for example Exps. 37 and 43, it is far more 

Each cylinder is delivered with a protective cap, which should be removed only when the cylinder has been chained against a laboratory table or a wall. Cylinders should always be ehained to prevent upset, which has been known to cause violent release of the gas or even bursting of the cylinder, with serious consequences. 

Regulator Operation. When it is desired to use gas from a cylinder, follow the 

Close the outlet needle valve and the diaphragm valve (turn the screw handle counterclockwise until it rotates freely). 

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Handling procedures for this highly reactive oxidant gas have been detailed [1]. Surplus gas is best burned with town- or natural gas, followed by absorption in alkali [2], More recent and comprehensive information is available [3],... 

The cheapest source of chlorine is the hazardous, yellow-green CI2 gas, supplied under pressure as a liquid. However, the supply of chlorine bottles (cylinders), the maintenance of a chlorinator (which permits the conversion of liquid chlorine into lower pressure gaseous chlorine), and the eductor and piping system is costly. It also requires first class health and safety handling procedures. 

Hazardous properties and handling procedures are summarised [1], Conditions under which it may explode by detonation, heat or shock were determined. It was concluded that it is potentially very explosive and precautions are necessary to prevent its exposure to severe shock or high temperatures in use [2], Later work, following two rail tank explosions, showed that shock caused by sudden application of gas pressure, or sudden forced flow through restrictions, could detonate the liquid. The stability and... 

Beryllium has been determined [764] in non saline waters and in sea water at oceanic levels of 2.30pM. Two ml of 0.1M EDTA, 2ml of 1.0M sodium acetate, 1.0ml of benzene and lOOpl of l,l,l-trifluoro-2-4-pentanedione were added sequentially to 150ml samples. Following liquid-liquid extraction using detailed handling procedures, the organic phase was mixed with 1.0ml of 1.0M sodium hydroxide (de-emulsifier), washed several times with distilled water and the resultant beryllium l,l,l-trifluoro-2,4-pentanedione complex analysed by gas chromatography with electron capture detection. 

A feature of the early problems of both Tsumeb and Metaleurop was the high downtime of the gas handling equipment. This contributed significantly to plant downtime, in the case of Tsumeb, centering on the operation of an evaporative gas cooler and in the case of Metaleurop, a Fluxflow waste heat boiler. In both cases, the process equipment selection occurred directly between the client and supplier without a formal review step by Ausmelt. This review has now been incorporated into Ausmelt s procedures for future projects, with a view to provide a benefit to both the client and technology supplier. 

Detailed information regarding compressed gas containers, pressure regulators, pressure relief devices, and valve outlet connections is contained in Chapters 5 through 9. Additional safe handling procedures for compressed gases can be found in CGA P-1 [7], and in CGA AV-1, an audiovisual safety training program of the same title. 

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