Compressed gas containers

Since the whole theme of this book is concerned with unexpected or concealed sources of energy, it is relevant to reiterate that compressed gases may contain a large content of kinetic energy over and above that potentially available from chemical reaction energy possibilities for the gas. A procedure for calculating available kinetic energy from rupture of compressed gas containers is found in... 

In addition to the above book, the Matheson (Gas Products) Company has some excellent information about compressed gases, compressed gas containers, and regulators in their catalog. ... 

Dry chlorine, in either the gaseous or liquid state, can be handled satisfactorily in carbon steel containers/cylinders. The dry chlorine is transported in cylinders up to 75 kg capacity or in one-ton containers. All containers, whether empty or full, must be stored in a dry area and protected from external heat sources such as steam pipes. If stored outdoors, they must be protected from direct sunlight, rain and snow. Chlorine containers should be segregate from other compressed gas containers. Containers must never be stored near anhydrous ammonia, hydrocarbons or flammable materials. The storage area must be well ventilated and underground storage must be avoided. 

Currently there are more than 200 different substances commonly shipped in compressed gas containers that can be considered compressed gases. The Department of Transportation (DOT) defines these materials based on their properties such as vapor pressure, flammability, toxicity, and physical state in the container. The specific definitions in this handbook according to DOT classification are in three Class 2 compressed gas divisions 2.1... 

Practices and precautions that must be followed when handling and using compressed gas containers include ... 

Compressed gas containers must not be exposed to direct heat, flame, or temperature extremes. Temperatures above 125°F (51.7°C) may result in excessive cylinder pressure and damage the container s physical integrity. If ice or snow accumulates on a container, thaw at room temperature. If containers are exposed to fire or struck by an electric arc, notify the gas supplier and obtain authorization from the supplier to ship such containers. 

Unless provided with a back-flow prevention system, compressed gas containers must not be connected to process piping where the container may be contaminated by the backflow of other process materials. Certain noncryogenic liquefied gases may be especially susceptible to this type of contamination due to their relatively low vapor pressures at ambient temperatures. In cases where such a possibility may exist, design consideration must include the use of check valves or traps, or both for this purpose. 

Where compressed gas containers are connected to a manifold, the manifold and its related equipment such as regulators and safety devices must be of the proper design for the product(s) they are to contain at the appropriate temperatures, pressures, and flows. 

Pressure-regulating devices, pressure relief devices, valves, cylinder connections, and hose lines should be inspected at frequent intervals to ensure they are undamaged and in safe working condition. Compressed gas containers with devices and appurtenances that appear to be damaged in any way should not be used, and the supplier should be contacted for instructions on the disposition of the container. 

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. 

The preferred and safest method of transporting compressed gases and cryogenic containers is to use vehicles designed and equipped for such purposes. A suitable vehicle is one that is adequately ventilated in the event of a product leak, and has an adequate method for securing any cylinders and containers during transport. However, as a minimum, the per-son(s), whether supplier or customer, transporting a compressed gas container in a vehicle must ... 

CGA C-9, Standard Color Marking of Compressed Gas Containers Intendedfor Medical Use, 3 ed.. Compressed Gas Association, Inc., 1725 Jefferson Davis Highway, Arlington, VA 22202. 

Fig. 3-2. Schematic example of CGA shoulder decal used to identify cylinder contents in accordance with Appendix A of CGA C-7-1992, Guide to the Preparation of Precautionary Labeling and Marking of Compressed Gas Containers [9].

This chapter describes and illustrates the major types of containers used to transport and store compressed gases, including those liquefied at very low or cryogenic temperatures. To keep pace with developments in the industry, CGA, through its technical committees, continually reviews and recommends changes to existing container specifications promulgated by the U.S. Department of Transportation (DOT) or Transport Canada (TC). Moreover, new specifications for compressed gas containers are also proposed from time to time. 

Readers should see Chapter 2 for general information on the safe handling of cylinders and other containers. Specific topics related to compressed gas containers are covered in Chapters 6 through 11. Information about the types of containers used with specific gases can be found in the gas monographs in Part II. 

Cylinders are the type of compressed gas containers most widely authorized for different means of shipment. They are generally the accepted type of container used to ship most gases... 

Almost all compressed gas containers in North America are fitted with pressure relief devices. A pressure relief device is a device that activates by pressure, temperature, or both to prevent pressure from rising above a predetermined maximum. Pressure relief devices prevent ruptures of normally charged cylinders when subjected to standard fire tests as required by Title 49 of the U.S. Code of Federal Regulations (49 CFR) Part 173.34(d)), or the equivalent provision of CAN/CSA B340 as required by the regulations of Transport Canada (TC) [1, 2, 3]. ... 

Requirements for stamp marking a portable compressed gas container are in the Hazardous Materials Regulations of the DOT and the regulations of Transport Canada (TC) [1, 2]. Such containers are constructed in accordance with a particular specification of the recognized authority. Depending on the particular type of container under consideration and the country, the recognized authorities may include DOT, TC, CSA, or the American Society of Mechanical Engineers (ASME), which publishes the ASME Boiler and Pressure Vessel Code [5]. 

Compressed gas containers for use in international trade must be marked in accordance with the requirements in the country of use and the United Nations (UN) agreements. Note that none of the requirements outlined in these publications are intended to supersede applicable federal, state, or provincial regulations such as the following ... 

General safety guidelines for storage and handling of compressed gas containers may be found in Chapter 2. 

Minimum pressure (minimum pressure rating) With respect to compressed gas containers, the term minimum pressure refers to the lowest service pressure rating authorized for cylinders of that specification in a particular gas service. For example, if specification 3A480 cylinders were authorized, specification 3A1000 or 3A2200 cylinders could also be used. 

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