In the world and Russian metal distribution, pipe products play a huge role, the production of which in recent years has been experiencing a period of rise and at the same time tightening the requirements for quality, assortment and functionality, as well as the economic efficiency of this industry. Today, these products are used in mechanical engineering and the fuel and energy complex, the defense complex and the construction industry, but the main consumer of steel pipes is certainly an oil and gas complex.
A wide range of steel pipes is available, which differ not only in the thickness of the walls and the size of the diameter, but also with stamps of steel and the shape of the blanks for them. This leakage of steel is characterized by high strength and certain plasticity with a small mass, however, they are subject to corrosion and gradual overgrowing from the inside with prolonged operation in a humid or aggressive environment.
In systems with slight pressure on the walls, welded pipes are used, for pipelines with high pressure – seamless, or whole. Basically used directly – and spiral -shovel, as well as water and gas pipeline structures made of ordinary carbon steel. For oil – and gas pipelines operating in conditions of large temperature differences, pipes made of high -quality thick -lobed steel are used. For grocery pipelines with aggressive solutions, stainless steel grades are used, and underground water intakes are equipped with casing seamless and drill metal rolled.
One of the important stages of modern pipeline production is anti -corrosion protection of these products in order to increase their durability and ensure the economic efficiency of their operation. Metallic ones protect against corrosion with passive and active methods. In the first case, insulating layers or special membranes are applied from the outer and inside of the rental, and in the second, electrical protection of the walls of the PROSITS is carried out. For example, cast-iron at manufacturing plants are covered with anti-corrosion mastics, steel from the outside is isolated by bitumen-polymer or bitumen-mineral, as well as ethylene or polymer coatings. The internal surfaces of steel water pipes on special equipment are covered with cement compositions by centrifugation. Those of them that are taken for use in household networks, as a rule, are protected from the influence of the external environment through paints and varnishes due to their efficiency and low labor intensity. Metals rental with expensive additives (Erbia or Tullia) are protected by zinc coatings, as well as the method of cathode protection.
Seamless pipes are made from alloy blanks in three stages:
-The ingot of faceted or round cross section is processed on the firmware, as a result of which the sleeve is obtained;
-The sleeve is rolled out on the mandrel, stretching it to the desired length;
-On the rolling camp, the workpiece is brought to the specified diameter size.
Seamless production is carried out on rolling mills of hot or cold rolling. The latter receive quality products with mirror inner and outer surfaces, which are used in shipbuilding, nuclear energy and air -hubby industries.
Welded are cheaper, but at the same time less durable and reliable. Direct welded products are produced from sheet steel by turning the workpiece into the cylinder and fixing the seam by electric arc welding. The second method is that the steel tape on special right equipment is curled up in a spiral into the tube and is fixed with welding. The price of this product is affected by the cost of metal, the method of production, the high cost of equipment.
The article was prepared by the specialists of the company “Electrac-STAL” .