How is the electrically welded steel pipe welded?

Where is the steel electric welded pipe used today? This product, which in modern conditions is widely used in various industries.

Application

As a rule, it is put where it is necessary to transport gaseous or liquid substances with a high degree of aggression. Therefore, the pipes of such a plan can be found in engineering, in the construction of heating systems of the main level.

Steel electric welded pipe is used in industry. Without it, you can not do without oil extraction, construction of scaffolding, furniture production, or even sports simulators. Its versatility, good performance characteristics, excellent opportunities for welding (including home) allow it to be used in domestic conditions for the formation and repair of utility networks.

Dimensions

Steel electric welded longitudinal pipes, GOST for which is number 10704-91, produce a certain unlimited length for a particular diameter. For example, with a value of up to 0.3 cm, the product should not be less than 2 meters in length, and if this parameter exceeds 15.2 cm, the length can not be less than 5 m. There are also dimensional versions where, for a given diameter, the length Pipe is within certain limits. So, for an indicator of up to 7 cm, the size of the article can range from 5 to 9 meters.

Production

What properties should such a pipe have? The steel electrowelded, straight-seam modification in production must have parameters corresponding to the state requirements for the articles used in this or that field. For example, pipes for oil and gas pipelines (main) are performed in accordance with GOST 20295-85. They are formed by welding electric arc or contact type (the latter using high-frequency currents) with different strength classes (from K34 to K60).

For the manufacture of products, heat-treated or hot-rolled steel (quiet or semi-cool) with a C content (carbon) of not more than 0.2% by weight is used. Its sheets are twisted into a tube, after which the edges of the sheets are heated by current and squeezed by rolls (electrode rings). The speed of such processes on special machines can be quite high (tens of meters of welding per minute, depending on the thickness of the walls). The operation is almost always accompanied by cutting the products of the required length with the help of cutting equipment.

The electric steel welded pipe can receive thermal treatment both along the entire length and only along the welded seam. The main metal of the product does not allow the presence of captivity, flaws, cracks, sunsets and delaminations. Surface imperfections of the acceptable level should not be corrected by welding (only by sweeping) in order to maintain the required degree of product reliability. Welded seams of pipes should not have fissures, cracks, pores, fistulas, slag inclusions that come out to the surface.

Cost

How expensive are electric steel welded pipes? The price for them, depending on the manufacturer, steel grade, diameter and wall thickness, can range from 32 to 45-48 thousand. When buying, always pay attention to compliance with GOST, because in its framework the products undergo the necessary tests, including the share of the viscous component, impact bending at different temperatures, tension, ovality of the article, the length of its deviation, the quality of the metal in Welded joint, etc.

Information about which product is planned to be purchased can be found from the stamp on the pipe. It must necessarily be placed at a distance of 10-150 cm from one end, marked with paint and include the year of manufacture, technical control data, steel grade, individual pipe number (batch), manufacturer's trademark .