Compressed Gas Cylinder Safety

C-14 Procedures for Testing of DOT Cylinder Pressure Relief Device Systems. Describes a new set of test procedures and apparatus for fire testing compressed gas cylinder safety (pressure) relief devices as required by DOT regulation, 49 CFR, Section 173.34(d). The procedures are applicable for cylinders which are less than 500 lbs. internal water volume and are designed to provide a means of testing to DOT requirements anywhere, with reliable test data and repeatable test results. Previous edition cited in 49 CFR (13 pages). 

Cylinder Safety If you plan to use compressed gas cylinders, safety should be a primary concern. A typical cylinder for analytical instruments has a pressure of 2000-3000 psig (140-210 bar) on delivery. A rupture at a cylinder valve causes rapid depressurization and can cause serious injury or structural damage to a lab (15). 

Compressed gas cylinders are used in gas welding. Except for the two cylinders on the welding cart, the oxygen and gas cylinders must be stored in separate areas. See chapter 2 for compressed gas cylinder safety. 

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. 

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. 

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. 

The first level of safety for quality and control is the construction of compressed gas cylinders. The specifications for their construction in North America is defined by Department of Transportation (DOT) and Canadian Transport Commission (CTC) regulations. Cylinders are made from carbon steel or alloy steel with seamless, brazed, or welded tubing that is formed by billeting (drawing flat... 

Figure 11.22 on the next page shows a typical compressed gas cylinder. You can see that it is built to withstand high pressures. There are other safety precautions as well, however. 

Some OSHA safety standards require signs, tags or markings to provide information on means of egress, exits, fire extinguishers, compressed gas cylinders and standpipe and hose fire-fighting equipment. 

For basic safety information on the handling of compressed gas cylinders, refer to CGA P-1, Safe Handling of Compressed Gases in Containers [3]. Also see Chapter 2. The storage, handling, and use of arsine in certain areas are regulated by fire codes such as Article 80 of the Uniform Fire Code [4]. 

What safety measures must be used when using compressed gas cylinders ... 

Chapter 9 covers specific essential information for anyone who has day-to-day involvement with compressed gas cylinders. The topics of marking, labeling, inspection, testing, filling, and disposition all contribute to ensuring the continued safety of the many millions of compressed gas cylinders currently in use. In the United States and Canada, there are approximately one-half as many compressed gas cylinders of various types as there are people. 

For any of the methods for hydrostatic testing, while the design and details of the apparatus may be adapted to suit individual requirements for a particular installation, the safety recommendations outlined in CGA C-1, Methods for Hydrostatic Testing of Compressed Gas Cylinders, should be followed. [18] Only properly trained personnel should be employed to perform the hydrostatic testing. 

V-1 American National, Canadian, and Compressed Gas Association Standard for Compressed Gas Cylinder Valve Outlet and Inlet Connections, Detailed dimensioned drawings of 65 valve outlet connections for almost 200 different products. The standard covers threaded connections, yoke outlets, and the Pin Index Safety System for flush outlet valves of the yoke type used for medical gases. (92 pages)... 

All DOT compressed gas cylinders use safety relief devices except those containing class A poison gases. In this case, the risk of exposure to the gas fumes is considered more hazardous than the chance of a cylinder failure. Gases that do not have pressure relief devices are usually allowed less maximum cylinder contents or use higher safety factor cylinders. 

Appropriate care in the handling and storage of compressed gas cylinders is essential. This safety guide contains the basic measures necessary to use compressed gas cylinders safely. Additional information pertaining to each specific gas can be found in the cylinder labeling and in MSDS. 

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