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Seamless metal pipes

Seamless (also called rolled) pipe is made of metal and has not a welded seam. It has the same strength along the whole length and has no weaknesses, unlike welded counterparts, which are made from sheet metal by welding at the edges. Welded pipes are cheaper and the technology of their production is much easier, but they are less durable that imposes limitations on their scope.

FIELDS OF APPLICATION SEAMLESS STEEL PIPES GOST 8732-78

Seamless steel pipe is used for piping which requires increased durability and reliability of each link in the chemical, petrochemical and oil industry. The extraction of natural gas and oil seamless metal pipes are a required component of the drilling units on which the transport occurs on the surface of the extracted raw materials. They are used in gas-lift compressor systems; they are also part of pipeline systems cracking.

Seamless steel pipe is often used in engineering in the production pipeline of large vehicles and industrial units. Also its use it finds in the aircraft industry, shipbuilding and many other sectors of the economy.

MANUFACTURE OF SEAMLESS STEEL PIPES

Manufacturer of seamless steel pipes is carried out on the pipe rolling machines which are equipped with automated control system to ensure mathematical accuracy in the production process and ensure high-quality products. Products are manufactured in strict accordance with state standards GOST 8732-78 and GOST 8731-78. They undergo an obligatory quality control. Depending on the desired diameter seamless metal pipes are manufactured by extrusion from a round billet or by puncture of a hot cylindrical billet. When you apply first technology get smaller diameter tubing.

There are 2 methods of manufacturing seamless steel pipes: cold and hot deformation. In the method of hot deformation, the billet is heated to 50-60 degrees above the threshold of crystallization of metals, without melting, acquires plasticity. For connecting the press it makes a hollow cylinder called the sleeve. For the final formation of regular geometric shape, alignment, wall thickness and set the desired diameter are subject to additional methods of treatment. The finished product is immersed in water and subjected to rapid cooling, and then finally calibrated. Processing ends with the cutting of pipes of a given length.

In the method of cold deformation of the billet immediately after the passage of the broaching mill is cooled and is pre-calibrated. Then the sleeve is heated to the recrystallization temperature of the metal to give it the ductility and relieve internal stresses and is run through rollers. Range is regulated by GOST 8734-75, and specifications are regulated by GOST 8733-74.

CHARACTERISTICS OF SEAMLESS PIPE

Seamless pipes have high tensile strength. The source material for melting is steel of various grades depending on the type of product and its purpose. Pipe length can reach 12.5 m, wall thickness in the range of 2.5-75 mm, and the diameter is 20-550 mm.