Kharkiv pipe steel seamless cold-smoked, hot-smoked steel st20, st45 6-630 mm (Metallobaza) delivery, cutting

Seamless steel pipes, depending on the production method, are produced according to two standards: hot-formed pipes are produced in accordance with GOST 8732-78; cold-formed pipes are manufactured in accordance with GOST 8734-75. GOST 8732-78 HOT-WORKED STEEL SEAMLESS PIPES Assortment pipe range According to this standard, the most thick-walled pipes are produced. The standard includes external pipe diameters from 20 mm to 550 mm. And pipe wall thicknesses from 2.5mm to 75mm. The standard regulates the pipe length of manufactured pipes: random length is made in the range from 4 to 12.5 m; measured length - within unmeasured; length, a multiple of the measured length, - within the random length with an allowance for each cut of 5 mm; approximate length - within unmeasured length; by agreement between the manufacturer and the consumer, it is allowed to manufacture pipes with a length that goes beyond the limits indicated for pipes of random length. The standard also includes limit deviations in diameter, wall thickness and pipe curvature per I m. The standard regulates the maximum deviations for the outer diameter of the pipe and the thickness of its walls. The full range table and the table of maximum deviations in the production of pipes can be found in the appendix to the article. GOST 8734-75 COLD-WORKED SEAMLESS STEEL PIPES Assortment This standard includes seamless steel pipes with outer diameters from 5 to 250 mm, with wall thicknesses from 0.3 mm to 24 mm. And also allows, at the request of the consumer, the manufacture of pipes of other diameters: a diameter of 4 mm with a wall thickness of 0.2 to 1.2 mm, and pipes with a diameter of 125 and 133 mm with a wall thickness of 2.0 to 20 mm, as well as dimensions of 29x5, 5; 32x8.5; 33x1.5; 33x8.0; 39x3.0; 41x5.5; 43x8.0; 44x3.0; 46x3.0; 46x6.0; 55x9.0; 58x4.0 and 84x8.0 mm. GOST 8734-75 also describes the tolerances for deviations in diameter and wall thickness, as well as in the curvature of the pipe section per linear meter. Areas of use Seamless steel pipes are used in places where high tensile strength is required, no weld seam (welded pipes have a high possibility of leaks). In hydraulic systems, as cylinders - incredible pressure is pumped into the cylinder to lift large loads, and in order for the cylinder to withstand such pressure, a seamless thick-walled steel pipe is used. Heat exchangers in high-pressure boilers - when superheated steam is heated, high pressure is formed inside the screen, and fire acts on the outside of the pipe. Here it is extremely necessary to have a margin of safety of the pipe and its durability. In the oil and gas industry - well drilling; casing; oil pumping; its transfer through the oil pipeline, as well as at some stages of oil refining or polymerization of gases, require huge pressures, thick walls reign supreme there. In the chemical industry, in addition to thick-walled seamless pipes, thin-walled pipes are often used. The use of thin-walled seamless pipes in the chemical industry is due to the use of highly toxic compounds, when it is not so much the strength of the pipe that is important, but the impossibility of leaks is important. Aviation, automobiles, shipbuilding – Lightness and strength of thin-walled seamless pipe are important here. Connection of seamless pipespipe seamless thick-walled The main criterion for choosing a method for joining seamless pipes is the wall thickness. Particularly thin-walled pipes without rolled threads are connected mainly by gas welding. Of course, you can cook them with electric welding, but without sufficient experience, this pipe will burn through. Threaded connection - pipe threads are cut both on a lathe and manually, the absence of a weld eliminates the violation of its integrity. The minimum wall thickness of the pipe under the thread must be at least 1.5 mm. On a particularly thin-walled pipe, a knurled thread is used (a die or cutter will simply cut through it). The threaded connection, subject to the assembly technology, provides high strength and good sealing. Thick-walled pipes - are cooked exclusively by electric welding (a gas burner simply cannot heat up a thick wall). To ensure reliable welding of a thick-walled pipe along the entire plane of the cut, it is necessary to chamfer along the entire depth of the wall, weld the joint with electrodes no thinner than a four. This will ensure high-quality welding of the seam throughout the depth. Seamless pipes are a type of rolled metal, the production technology of which provides for the absence of any seams along the entire length of the products. The weakest point of a welded pipe is the seam. Despite the constant improvement of technologies, due to additional heating during welding, the metal structure along the joint becomes brittle, and the weld itself has a looser molecular structure, subject to corrosion destruction. Steel seamless pipes do not have such a flaw; a monolithic cylindrical shape serves as a reliable protection against leaks.