These same prop-erties give acetylene its value as a high temperature cutting and welding gas with a very wide range of applications. Acetylene for instance, the gas used in an acetylene torch used to cut metal will combust or explode anywhere from 2.5% concentration all the way up to 100%. Pure acetylene is a unique gas with hazards that arise from its high energy bonds and flammability. Store flammable gas in a cold, closable and dark area is critical. Chemical Composition: An acetylene molecule is fabricated by the composition of two carbon atoms and two hydrogen atoms. It may react explosively even in the absence of air at elevated pressure and/or temperature. A demonstration of the explosive potential of even a small amount of acetylene mixed with the right amount of oxygen. As a result special precautions are required during its production and handling. Acetylene . No water or water-based foams shall be used in such situations. When mixed with air, the explosive range is from 2.5% to 82%. It is a recovered side product in production of ethylene by cracking of hydrocarbons.Approximately 400,000 tonnes were produced by this method in 1983. Read Safety Data Sheet before use. Acetylene leaks, no matter how small, can have serious consequences. Hazards of Acetylene Gas. As the gas is highly combustible when comes in contact with the oxygen, it is recommended to ensure safety measures to avoid accidents. Compressed Acetylene Gas (215) 898-4453 Office of Environmental Health and Radiation Safety (EHRS) www.ehrs.upenn.edu Rev. According to legislation, this gas should not be compressed freely to more than 20-22 lbs. The compressed or liquified unsaturated hydrocarbon like acetylene is a highly explosive gas. Detonation limits have been determined. Precautionary Statements: Read label before use. Acetylene is commonly used in gas cutting. Every gas has a range in which it can combust or burn. For safety reasons, the acetylene is dissolved in acetone or dimethylformamide in the gas receptacle. If venting or leaking gas catches fire, do not extinguish flames. This produced acetylene and oxygen at the same time. Special hazards arising from the substance or mixture Fire hazard : EXTREMELY FLAMMABLE GAS. Dangerous stuff. It forms explosive mixture with the air. If a cylinder has been transported, it must be left to settle in an upright position on arrival. Correct set-up of oxygen/acetylene equipment. Order 1947 made under the Explosives Act 1875) defines acetylene gas at pressures of more than 9psi (0.621 BAR) above that of the atmosphere as being an 'explosive' and requires that it may not be held: (a) at pressures in excess of 9psi (0.621 BAR) above that of the atmosphere, except as approved by the Secretary of State, nor 1.1% vol. Some tips for safely using and storing acetylene: Always use acetylene in a well vented area, and never in a confined space. Acetylene is sparingly soluble in water but readily soluble in an acetone solution. Fire hazard : EXTREMELY FLAMMABLE GAS. If venting or leaking gas catches fire, do not extinguish flames. For a long time, it was assumed to have the unusual property that on ignition it does not evolve any gas, only decomposing through the reaction: Ag 2 C 2 (s) → 2 Ag (s) + 2 C (s) However, free acetylene can undergo explosive decomposition when compressed or overheated. Acetylene is the most common gas used for fueling cutting torches in both general industry and the mining industry. Acetylene is highly shock sensitive and is a flammable gas that is unstable in certain conditions, which may decompose explosively. Flammable Gas Incompatibilities & Reactivities Zinc; oxygen & other oxidizing agents such as halogens [Note: Forms explosive acetylide compounds with copper, mercury, silver & brasses (containing more than 66% copper).] Flashback Prevention . Acetylene is commonly used for fueling cutting torches in both general industry and the mining industry. It is very flammable and can bring disastrous accidents if not handled with precautions. Flammable vapors may spread from leak, creating an explosive reignition hazard. Stating that an acetylene cylinder is equivalent to x kg of TNT is little different to saying the same about a car’s petrol tank, a camping gas or propane cylinder, or even your kitchen’s gas hob being equivalent to a certain amount of high explosive. Its lower and upper explosive limits in air are 2.5% and 93%, respectively. Acetylene is a colorless, combustible gas with a distinctive odor. Highly unstable, acetylene gas, together with air or oxygen easily forms an explosive mixture. Pure acetylene is a colourless gas with a pleasant odour; as prepared from calcium carbide it usually contains traces of phosphine that cause an unpleasant garliclike odour. acetylene gas is not explosive. It helps to burn the object at an increased rate. Care must be taken to ensure that extinguishing the fire will not increase the hazard of explosion or lack of oxygen by allowing acetylene to accumulate in an unventilated area. 5.2. For the exact product composition, please refer to Air Products technical specifications. Failure to do so can cause quality problems with acetone liquid getting into the gas. This gives the liquid acetone time to return to its correct place in the porous mass. In welding and metal cutting, acetylene is widely used. In addition to the acetylene, oxygen is widely used too for gas cutting. • Acetylene regulators clearly indicate pressure at or above 15 psig with red marking on the gauge. This involved some 6 cu m of acetylene and 18 cu m of nitrous oxide, and caused severe structural damage. A violent, explosive decomposition reaction can occur. I did it outside and the wind blew out my burning splint. Acetylene gas forms a explosive mixture in contact with air. Our member concluded: Flashbacks are commonly caused by a reverse flow of oxygen into the fuel gas hose (or fuel into the oxygen hose), producing an explosive mixture within the hose. Acetone . Acetylene fires arising from wet calcium carbide inside a building shall be extinguished by using dry-powder extinguishers or carbon dioxide. Explosive character. Pure silver acetylide is a heat- and shock-sensitive high explosive. Ammonia The decomposition may or may not give rise to explosion, depending on conditions. Unlike oxygen, acetylene cannot be compressed freely with safety to a pressure greater than 30-40 lbs. A back flow preventive device is used in case of piping the gas. per square inch. 4.0% vol. This gas has the widest explosive range of any commonly used gas. This post specifically concentrates on hazards as well as safe storage of compressed acetylene gas cylinders along with some additional information. (8) is 600 Pa s, which is much less than the right side. At 40 times original pressure, Pex is 60 MPa. Bulk gas storage has a minimum separation of 3 meters. This paper considers the explosion of an acetylene gas cylinder, which occurred in 1993 in Sydney. Therefore, acetylene stored with acetone solution under 10 atm pressure, acetone absorbed some porous materials for settings safety of the cylinder or suppliers tank. Thus, their careful handling and storage is very important. When acetylene is liquefied, compressed, heated, or mixed with air, it becomes highly explosive. Acetylene gas leaking from a supply tube was ignited by the source flame and a minor explosion occurred, and appears to have damaged both gas supply lines, which led to a second major explosion and fire. Acetylene is a colorless gas often used as a fuel by plumbers and welders, among other tradespeople, for welding, cutting, and similar processes. Acetylene 74-86-2 100 % Concentration is nominal. 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