Cylinder compressed gas

A cylinder of compressed, non-liquefied gas, may be filled to the service pressure stamped on the cylinder shoulder if the fill temperature is 70°F or less. If the gas is a non-liquefied, nonflammable, and nonpoisonous gas then a 10% overfill is allowed if the cylinder has passed an extra overpressure test as indicated by a + sign stamped following the hydrotest date. 

Compressed gases have properties that make their handling more hazardous than the handling of liquids and solids. These properties include pressure that can lead to equipment leakage and easy diffiisivity in air to spread the leakage quickly. Flammable gases may have low flash points and toxic gases may not be easily detected visually or by odor. 

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Specialty Gases. The specialty gases are generally more reactive than the bulk gases and usually have low volume flow requirements in their appHcations. Historically, these have been deHvered almost exclusively in standard compressed gas cylinders. However, as the need for increased quantities has arisen, bulk specialty gas supply systems utilising larger ton-sized containers and tube trailers are being developed. 

For distributing larger quantities of gaseous helium, argon, and occasionally neon, a number of large, horizontal, compressed gas cylinders are manifolded on tmck semitrailers (called tube trailers) or railroad cars. Like individual cylinders, these serve both as transport containers and rental storage containers. Capacities of tube trailers range from about 300 to 5,000 m (10,000—175,000 fT) of gas. 

Small shipments of ethylene oxide ate made in either compressed gas cylinders up to %).l (30 gal) or in lAl steel dmms (61 gal). Very large shipments... 

Do not use oil, grease or joining compounds on any fittings for compressed gas cylinders. 

Precautions for handling carbon monoxide in compressed gas cylinders in addition to those given in Table 9.3 include ... 

Gas storage cabinets are used to contain compressed gas cylinders containing toxic, flammable, or corrosive gases. 

The chlorine, obtained from a compressed gas cylinder, was passed through a wash bottle containing concentrated sulfuric acid before being passed into the reaction solution. 

Gases such as methane are sold and shipped in compressed gas cylinders. A typical cylinder has a volume of 15.0 L and, when full, contains 62.0 mol of CH4. After prolonged use, 0.620 mol of CH4 remains in the cylinder. Use the van der Waals equation to calculate the pressures in the cylinder when full and after use, and compare the values to those obtained from the ideal gas equation. Assume a temperature of 27 °C. 

The colors purple, brown, black, and gray have not been assigned a safety connotation. Specific color codes are also employed in the identification of alarms panel indicators, piping, compressed gas cylinders, electrical wiring, fire sprinkler temperature ratings, etc. Although these sometimes do not correspond with similar meanings. 

Seamless steel pressure vessels are the most common method in use today for hydrogen transportation at short distances (<200 km) and when small quantities are involved (up to about 500 kg). The different vessel options include cylinders, manifolded cylinder pallets and tube trailers. While single cylinders or manifolded pallets are trucked to the destination and off loaded, tube trailers, which consist of several steel cylinders mounted to a protective framework, are often left in place and replaced when empty. Transporting hydrogen in liquefied form is seven times more efficient in terms of actual hydrogen weight transported than using compressed gas cylinders. 

The burner used for flame AA is a premix burner. It is called that because all the components of the flame (fuel, oxidant, and sample solution) are premixed, as they take a common path to the flame. The fuel and oxidant originate from pressurized sources, such as compressed gas cylinders, and their flow to the burner is controlled at an optimum rate by flow control mechanisms that are part of the overall instrument unit. 

The sources of acetylene, nitrous oxide, and sometimes air are usually steel cylinders of the compressed gases purchased from specialty gas or welders gas suppliers. Thus, several compressed gas cylinders are usually found next to atomic absorption instrumentation and the analyst becomes involved in replacing empty cylinders with full ones periodically. Safety issues relating to storage, transportation, and use of these cylinders will be addressed in Section 9.3.7. The acetylene required for atomic absorption is a purer grade of acetylene than that which welders use. 

All precautions relating to compressed gas cylinders must be enforced—the cylinders must be secured to an immovable object, such as a wall they must have approved pressure regulators in place they must be transported on approved carts etc. Tubing and connectors must be free of gas leaks. There must be an independently vented fume hood in place over the flame to take care of toxic combustion products. Volatile flammable organic solvents and their vapors, such as ether and acetone, must not be present in the lab when the flame is lit. 

It is obvious that the flow rate must be precisely controlled. The pressure from the compressed gas cylinder of carrier gas, while sufficient to force the gas through a packed column, does not provide the needed flow control. Thus a flow controller valve is built into the system. The flow rate of the carrier gas, as well as other gases used by some detectors, must be able to be carefully measured so that one can know what these flow rates are and be able to optimize them. Flow meters are commercially available. However, a simple soap bubble flow meter is often used and can be constructed easily from an old measuring pipet, a piece of glass tubing, and a pipet bulb. See Figure 12.10. With this apparatus, a stopwatch is used to measure the time it takes a soap bubble squeezed from the bulb to move between two graduation lines, such as the 0- and 10-mL lines. The commercial version uses an electronic sensor to measure the flow rate based on the bubble movement. See Workplace Scene 12.3. 

Apparent near the bench on which the GC unit sits are pressure-regulated compressed gas cylinders of hydrogen and air (in addition to the carrier gas, helium or nitrogen). Metal tubing, typically ]/8-in. diameter, connect the cylinders to the detector. A needle valve is used for flow control. These valves are located in the instrument for easy access and control by the operator. 

In the early 1970s, K. Kordesch modified a 1961 Austin A-40 two-door, four-passenger sedan to an air-hydrogen fuel cell attery hybrid car (23). This vehicle used a 6-kW alkaline fuel cell in conjunction with lead acid batteries, and operated on hydrogen carried in compressed gas cylinders mounted on the roof The car was operated on public roads for three years and about 21,000 km. 

The checkers used a cooling bath prepared from ice and sodium chloride and dried the hydrogen chloride obtained from a compressed-gas cylinder by passing the gas through a trap filled with concentrated sulfuric acid. 

Every five years, all hoses should be tested to 1 times the container pressure at 130°F (54.4°C). Also, every five years the cylinders should be inspected per DOT requirements. For containers in continuous service, a visual inspection per CCA C-6, Standard for Visual Inspection of Steel Compressed Gas Cylinders may be conducted. The cylinder does not need to be emptied and cylinder should not be stamped. 

CGA C-6.19. Standard for Visual Inspection of Steel Compressed Gas Cylinders. Compressed Gas Association, Chantilly, VA. 

Burkhardt, M. R N. I. Maniga, D. H. Stedman, and R. J. Paur, Gas Chromatographic Method for Measuring Nitrogen Dioxide and Peroxyacetyl Nitrate in Air without Compressed Gas Cylinders, Anal. Chem., 60, 816-819 (1988). 

Inert gases are generally available in high-pressure compressed gas cylinders and, in some cases, in medium-pressure Dewars. Details on handling high-pressure compressed gas cylinders are given in Chapter 10. The present chapter will concentrate on the purification of inert gases. 

B. Safe Delivery Of Gases. The vast majority of compressed gas cylinders are supplied with efficient on-off valves which provide no significant flow or pressure control. CAUTION It Is necessary to eqnip a compressed gas cylinder with some means of controlling the pressure and/or flow of the gas being deltv-... 

Steere, N. V. Ed., 1971, Handbook of Laboratory Safety, The Chemical Rubber Co. Press, Cleveland. Contains a chapter on compressed gas cylinders and cylinder regulators. 

Small shipments of ethylene oxide are made in either compressed gas cylinders up to -0.1 m3 (30 gal) or in 1A1 steel drums (61 gal). Very large shipments >40 m3 (10,000—25,000 gal) are made in insulated, type 105J100W or other DOT approved tank cars. For further information on the shipping and handling of ethylene oxide, see References 9 and 227. 

Compressed gas cylinders. Under certain circumstances, cylinders of compressed gas may constitute major explosion and fire hazards and, despite their apparent robust construction, they should always be handled with care.7... 

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