Question

Describe in brief the equipments required for oxy-acetylene welding.

Answer 1

The following equipments are required for oxy-acetylene welding. 1. Welding torch or Blowpipe: It is the tool for mixing two gases in the desired volumes and burning the mixture at the end of a tip. It has a handle to carry it and two inlet connections for gases at end. Each inlet has a valve to control the volume of oxygen or other gas. Two gases from two paths mix up in a mixture and flame is produces by igniting the mixture at the tip of the torch. 2. Pressure Regulator: The function of pressure regulator is to reduce the pressure from the cylinder and to maintain it at constant value regardless of the pressure variation at the source. It is also used to adjust the pressure of the gas to torch. Changes in the pressure can be made simply by turning the handle at the regulator. There are two types of pressure regulators viz., single stage and double stage. 3. Hose and Fittings: Two hoses to carry oxygen and acetylene separately are required . They connect the regulator mounted on cylinders to the torch. Generally Green colour is adopted for oxygen and red for acetylene. These should be strong, durable, non-porous, light and flexible. To avoid explosion , oxygen fittings should never be greased or oiled. Special hose fittings and connections are provided for attachment to the torch and pressure regulators. 4. Cylinders: The gases are generally stored at high pressure in the steel cylinders. For oxygen which is obtained commercially, cylinders are made up of drawn-steel without seams and carefully heat treated as to develop great strength and toughness. The cylinder is also equipped with high pressure valve and valve-protector cap. It is charged at a pressure of about 150 kg/cm2 and temperature about 20⁰C. A safety fuse plug is also provided so as to release oxygen in case , temperature inside increases. Acetylene cylinders are closely packed with absorbent filler , which is saturated with acetone. 5. Goggles: These are very essential to protect eyes. These are fitted with coloured lenses that prevent harmful heat and the ultraviolet and infra-red rays. 6. Spark Lighter: It provides a convenient and instant means for lighting the welding torch. It consists of a pointed stone and a rough surface which produce a spark when rubbed together. 7. Apron: This protects the clothes of operator from dirt and danger and keeps him alert. 8. Gloves: These are essential to protect hands. 9. Ventilation equipment: It is essential particularly when welding in confined spaces. Fumes given by welding are harmful for lungs. 10. Welding rods: Theoretically the composition and properties of the welding rod should match with the base metal very closely. Therefore proper welding rods should be chosen for various non-ferrous and ferrous metals. 11. Fluxes: in welding of certain metals, fusion of the weld does not takes place very readily particularly when the oxides of the base metal have a higher melting point than the metal itself.