Metal pipes are hollow products of high-quality metal rolling. Such products have found wide application in the transportation of liquids and gases, in construction, engineering, shipbuilding, and the production of various finished products. In the catalogs of manufacturers there is a large number of varieties of metal pipes, the characteristics of which significantly affect the operational performance of finished structures.
Distinctive characteristics of pipes
The assortment of metal pipes is quite large and includes dozens of different products. Traditionally, metal products are distinguished by the following indicators:
- section type - it can be round and profile;
- production method - according to this feature, products are welded and seamless;
- type of steel - the material used for the manufacture of metal, affects the service life, strength and other indicators;
- diameter - it affects the size and throughput of pipes;
- wall thickness - affects the strength and weight of the structure;
- the presence of additional coating (galvanized and non-galvanized).
Section Types
The most common option is considered to be a round pipe, which is used almost everywhere: laying water pipes, sewers, gas pipelines, ventilation, reinforcing construction objects, assembling equipment, and the automotive industry.
Less demanded, but extremely important are pipes with square and rectangular sections. Their important characteristic is flexural strength and low weight. This makes it possible to use such products in construction instead of heavy cast structures.
Quite rarely, options with an oval and arched profile are used. They are very convenient to use if there is a shortage of space, because the throughput of the pipe remains good.
Manufacturing methods
When choosing a pipe, it is important to consider the method of its manufacture.
Seamless products are the most reliable metal pipe capable of withstanding high pressure. Its distinguishing feature is the absence of a weld. It is made in two ways.
- Of special cast billets (they are also called pigs). During production, the blank is heated to high temperatures and processed on machines (pulled, drilled, rolled, calibrated).
- Casting method. In this case, apply a special form with a rod in the middle. The molten metal is poured into a mold and cooled. As a result of such actions, metal products of the desired thickness and diameter are obtained.
A welded pipe is another option. You can recognize this metal product unmistakably - along the wall the weld stretches along the entire length of the product. Such pipes are made of sheet material of the desired thickness. First, the sheets are cut (the desired length and width are attached). After that, a piece of steel is rolled out on the machines and the desired profile and diameter is attached. Indirect seam options are also possible.
The strength of such products is slightly lower, but the cost is very affordable. At the same time, consumers can not worry about the reliability of the finished product. After manufacturing and welding, the pipes and seam are tested for strength.
Types of steel
For the production of metal products, different types of steel are used, which differ in chemical composition and physical characteristics: yield strength and strength, hardness and impact strength. The following types of steels are distinguished.
- Carbon structural. This category includes steels 10, 15, 20, 08 and St3-6sp. They are used for laying high pressure pipelines, as well as gas pipelines, heating systems and heaters.
- Low alloy and alloy steels. Among them are 17GS, 10G2, 15XM, 09G2S, 12X1MF and some others. The scope of their use is the installation of oil and gas pipelines, pipelines for hydrogen sulfide-containing and corrosive environments.
- Alloyed stainless heat-resistant and corrosion-resistant steels. The list of such steels includes 12X18H12T, 08X18H10T, 03X18H11, 12X18H10T and 08X18H12T. You can use this metal in a moderately hazardous environment and at high temperature.
Diameter of round metal pipes
Metal rolling manufacturers offer a wide range of products that vary in diameter and wall thickness. There are certain standards for each type of pipe .
The diameter of metal pipes with a circular cross section may vary depending on the manufacturing method.
Water and gas pipes are another variety. The outer diameter of such products varies from 25 mm to 550 mm. They are produced by the hot-rolled method without a weld (rolling and deformation after heating) and can be either thick-walled or thin-walled.
Longitudinal welded products have slightly different standards. Their outer diameter can reach from 8 to 1620 mm.
Profile pipe sizes
If we talk about square metal pipes, then the smallest size is considered to be the sides 10 * 10 mm, the largest is the profile pipe with dimensions 180 * 180 mm. The wall thickness varies from 0.8 mm to 14 mm. The quality of manufactured products is clearly controlled by GOST 8639-82.
For metal profile pipes with a rectangular section, the parameters and dimensions are slightly different. The dimensions of the cross section for the smallest pipe are 15 * 10 mm, for the largest - 180 * 150 mm. In this case, the wall can be from 0.8 to 12 mm in thickness. The quality of this high-quality metal rolling is regulated by GOST 8645-68.
Galvanized and non-galvanized surface
Metal pipes are often produced with galvanized coating. What does it mean? During production, some metal products are coated on top with a zinc solution, which forms a thin film on the surface. Such a layer prevents the metal from contacting with the liquid, which means it has anti-corrosion properties.
Finished products from such products will last much longer than those made from ordinary metal pipes.
When choosing pipes for a particular project, a number of characteristics should be considered. Including dimensions of metal pipes, their thickness and type of steel. These indicators directly affect the final cost of work and the life of the facility. In other words, carefully approaching the choice of metal, you can reduce the cost of products without compromising on quality.