The use of acetylene. Acetylene welding

To understand where acetylene is used, it is necessary to study and understand what it is. This substance is a flammable, colorless gas. Its chemical formula is C 2 H 2 . Gas has an atomic mass of 26.04. It is slightly lighter than air and has a pungent odor. The production and use of acetylene is carried out only in an industrial environment. This substance is obtained from calcium carbide by decomposition of the component in water.

acetylene use

What is dangerous acetylene

The use of acetylene is limited by its extraordinary properties. This gas is self-igniting. This happens at a temperature of 335 ° C, and its mixture with oxygen - at a temperature of from 297 to 306 ° C, with air - at a temperature of from 305 to 470 ° C.

It is worth noting that technical acetylene is explosive. This was when:

  1. An increase in temperature to 450-500 ° C, as well as at a pressure of 150-200 kPa, which is equal to 1.5-2 atmospheres.
  2. A mixture of acetylene and oxygen at atmospheric pressure is also dangerous if it contains 2.3-93% of acetylene. An explosion can occur from intense heat, an open flame, or even a spark.
  3. Under similar conditions, an air-acetylene mixture bursts if it contains 2.2-80.7% acetylene.
  4. If the gas comes into contact with a copper or silver object for a long time, acetylene explosive silver or copper may form. This substance is very dangerous. An explosion can occur from a strong blow or as a result of an increase in temperature. Work with gas carefully.

Substance features

Acetylene, the properties and application of which has not been fully studied, as a result of an explosion can lead to an accident and severe damage. Here are some details. An explosion of one kilogram of a given substance releases 2 times more thermal energy than an explosion of the same amount of TNT, and one and a half times more than an explosion of one kilogram of nitroglycerin.

areas of application of acetylene

Acetylene Applications

Acetylene is a combustible gas that is used in gas welding. Often it is used for oxygen cutting. It should be noted that the combustion temperature of a mixture of oxygen and acetylene can reach 3300 ° C. Due to this property, the substance is most often used in welding. Acetylene is usually replaced by natural gas and propane-butane. The substance provides productivity and high quality welding.

Gas supply for cutting and welding can be provided from an acetylene generator or from cylinders with acetylene. To store this substance usually use white containers. As a rule, they have the inscription "Acetylene", applied in red paint. It is worth considering that there is GOST 5457-75. According to this document, technical dissolved grade B acetylene or a gaseous substance is used for metal processing.

acetylene welding

Acetylene welding: check

The technology of welding with this gas is quite simple. However, when working with a substance, patience and care are required. For welding, special torches are usually used, marked 0-5. Her choice depends on how thick the welded parts are. Please note that the larger the size of the burner, the greater the flow rate.

Acetylene welding is carried out only after the equipment is checked and adjusted. In this case, pay attention to the tip number and the number of the gas supply nozzle, which is located near the burner handle under the nut. Also check all seals.

acetylene properties and application

Welding process

The use of acetylene in welding should be carried out carefully and in accordance with certain rules. To start, the burner should be blown with gas. This must be done until the smell of acetylene appears. After that, the gas is ignited. In this case, oxygen should be added until the flame becomes more stable. Acetylene pressure should be from 2 to 4 atmospheres from the pressure reducer and oxygen from 2 atmospheres.

Welding ferrous metals requires a neutral flame. It has a clearly defined crown and can be conditionally divided into three bright parts: the core is a bright blue color with a greenish tint, the restored flame is a pale blue, the torch flame. The last two zones are working.

Before starting work, all parts must be cleaned and then adjusted to each other. When working with the burner, the left and right methods are also used. In the latter case, the seam cools slowly. The filler material typically moves behind the burner. With the left method, the elasticity and strength of the seam increases. In this case, the flame is directed from the place of welding. The filler material should only be introduced into the weld pool after it has moved to the next position of the torch.

production and use of acetylene

Safety regulations

The use of acetylene without skills and experience is prohibited. There are several rules that should be observed when working with a substance:

  1. The content of acetylene in the room in the air must be constantly monitored. To do this, use special automatic devices that are able to notify about an excess of gas concentration. This indicator should not be more than 0.46%.
  2. The areas of application of acetylene are completely different, but most often it is used in welding. When working with cylinders filled with this particular gas, care should be taken. Do not place containers near open flames or near heating systems. In addition, it is forbidden to work with cylinders that are in a horizontal position, as well as if they are not fixed and faulty.
  3. When working with acetylene, use exclusively non-sparking tools, electrical equipment and lighting in an explosion-proof design.
  4. If acetylene leaks from the cylinder, close the container valve quickly. To do this, you can use a non-sparking special key. A leak can only be detected by sound or smell.
    technical acetylene

What to do if a fire occurs

Improper use of acetylene can lead to sad consequences. This gas explodes and causes severe destruction. What to do if a fire breaks out?

  1. If a fire occurs, immediately remove all containers filled with acetylene from the danger zone. Those cylinders that remain should be constantly cooled with ordinary water or a special composition. Tanks should be completely cooled.
  2. If the gas that escapes from the cylinder is ignited, immediately close the container. To do this, use a non-sparking key. After this, the container must be cooled.
  3. In case of severe fire, extinguish the fire only from a safe distance. In such a situation, it is worth using fire extinguishers filled with a composition containing a phlegmatizing nitrogen concentration of 70% by volume, also carbon dioxide 75% by volume, sand, water jets, compressed nitrogen, asbestos cloth and so on.


All Articles