Let`s consider the application of argon welding for pipelines repair and installation.
Technological pipelines are pipelines through which the delivery and removal of process fluids (medium) takes place, to ensure the functioning of the enterprise, plant, shop. Such pipelines are used practically in all branches of industry: chemical industry, food industry and breweries, pharmaceutical, agriculture and industrial complex, metallurgical branch. Pipelines can be made of various materials: low-medium-carbon steels, low-medium-high-alloy steels, titanium and its alloys. The most of steels used for mounting technological pipelines are stainless steels: AISI-304; 308; 316; 321, according to euro norms: EN-1.4301, 1.4307, 1.4404.1.4878, as they provide sufficiently high corrosion resistance for slightly aggressive environments: product delivery systems, washing systems for food and chemical enterprises, technological blocks and communication blocks, pipelines and pipelines, pipelines industrial enterprises, internal shop and interdepartmental pipelines, strapping pipelines. In the case of a high aggression environment (chemical plants using chlorine), it is advisable to use pipes made of titanium and its alloys or high-alloy steels that provide enhanced corrosion resistance to the medium used.
For the installation of process pipelines, the corresponding supports are used, which are manufactured according to: 14911-82, 36-94-83 standards. Pipeline supports can be made of different materials, which is determined by the environment of their use.The most accessible type of welding for these works is argon-arc welding.
The technology of this welding is quite simple: In an inert gas environment – argon or helium, the electric arc burns. The electrode is non-melting, since it has a very high melting point, the electrode material is tungsten. The welder performs the work by feeding the welding rod into the fusion zone (welding tray). The welding process can also take place without the addition of filler material to the welding tray, this function is assumed by the metal of the pipe – the base metal and this method is called the pendel.
For qualitative welding of the pipe joint, it is necessary:
1. Fine adjustment of the welding current and the capabilities of the welding machine.
2. Presence of mounting equipment.
3. The experience of the welder – welding joint.
Pipes used for installation can have a different diameter – from 10 mm to 1021 mm. and more, different thickness of the pipe wall.
Accordingly, a pipe having a wall thickness of up to 2.6 mm can be welded without cutting the edges, which in turn involves welding with or without filler material. Pipes having a wall thickness of more than 3 mm are welded to the cutting edge, i.e. at a certain angle, the end of the pipe is cut to provide access to welding manipulations inside the welding joint. The welding process must ensure the province, the formation of a continuous weld inside the welding joint (pipe).
In order to ensure the performance of the cook, i.e. quality welding joint, a sufficiently high level of preparation of the welding specialist is necessary.
In Ukraine, there are highly skilled specialists who work in the field of installation of technological pipelines of medium and high alloy steels, having the necessary welding equipment and accessories for professional pipe mounting.