High pressure gas cylinders

Because oxygen is relatively insoluble in water, it can be collected by water displacement using the same apparatus employed to collect hydrogen (Figure 14.1). Oxygen is seldom prepared in the laboratory, though, because it is commercially available as a compressed gas in high-pressure steel cylinders. 

Nitrous oxide is contained and transported in its liquid phase in high-pressure gas cylinders or in liquid cylinders. It is transported as a liquefied compressed gas under high pressure in cylinders and at lower pressures and reduced temperatures in refrigerated cargo tanks and insulated portable tanks. Nitrous oxide is stored in a foam-insulated tank accompanied by a refrigeration unit, which is similar to the tank used for carbon dioxide. 

There are several well-known examples of processes which do not violate the first law, but which do not occur naturally Suppose, for example, that, we have a cylinder separated into two compartments by means of a partition (Figure 5.1), with on one side a gas at high pressure and on the other a gas at low pressure. If the diaphragm is ruptured, an equalization of pressure will occur. However, the reverse of this process... 

Smaller quantities of gas at high pressure are usually stored in bottle-shaped gas cylinders. Although convenient to handle, they suffer from the disadvantage that their thick steel walls make them very heavy. Cylinders must be held in position by securing chains and they must not be banged or exposed to sources of heat. Owing to the severe risk in the event of fire, only the minimum number of cylinders required for immediate use should be stored at the plant. 

Some gases may combine several of the above hazards. For example, a cylinder of hydrogen gas combines high pressure with the flammable hazard. Liquid oxygen combines the oxidizer with the low-temperature hazard. 

Air can be compressed at the point of use for most practical applications. To meet needs for air of special purity or specified composition (as in certain medical, scientific, industrial, fire protection, undersea, and aerospace uses), it is purified or compounded synthetically and shipped in cylinders or tube trailers as a nonliq-uefied gas at high pressures. 

Gas systems contain an extinguishant gas at high pressure supplied from gas cylinders. 

Natural gas, which is mostly methane, is widely used as a fuel. In the chemical industry, methane is used heavily as a raw material for making important products that include acetylene, ammonia, ethanol, and methanol its chlorination also yields carbon tetrachloride, chloroform, methyl chloride, and methylene chloride. It is used to produce carbon black for use in the manufacture of rubber products and printing inks. The burning of high-purity methane is used to make carbon black of special quality for electronic devices. Natural gas has seen limited use as a motor fuel handled as a compressed gas in high pressure cylinders or liquid dewars. 

Under the appropriate regulations, nitrous oxide is shipped as a refrigerated liquid, typically 0°F and 268 psig (—17°C and 1848 kPa), and as a liquefied compressed gas in high-pressure cylinders under ambient conditions. [7] and [8] See Table 2 concerning the vapor pressure and temperature properties of nitrous oxide. 

Storage and Shipment. VDF or HFC-1132a is stored and shipped in gas cylinders or high pressure tube trailers without polymerization inhibitor and is placarded as flammable compressed gas. Terpenes or quinones can be added to inhibit polymerization. Elf Atochem North America, Inc. and Ausimont USA, Inc. supply VDE in the United States other producers are in Japan and Europe. 

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