Rectangular pipes: advantages of a profile pipe and assortment
Despite the changing crises, private construction continues to grow rapidly. Brick, concrete and wood are considered classic materials for building construction, but construction has never been without metal, as profiled sheets and grids are required, floor beams, profiles for frameworks.
By welding, from metal it is possible to create any constructions, and the connection is not worse in strength, than a metal array. exept this, metal elements can be forged under heat, deform and bend under pressure. Any metal structures will always be more compact and lighter than the same functions of reinforced concrete and stone elements. With proper care and proper assembly, they are much more durable, Moreover, if you choose a certain brand of steel or metal from the range, which will provide the workpieces corresponding to certain conditions of operational quality.
Profile metal pipes in our country began to be used relatively recently, but the popularity of rectangular and square pipes is constantly growing. They are getting cheaper and better, their range by types of section and the sizes expands.
Definition of a profile pipe
Usually, when it comes to pipes, many represent an ordinary cylindrical object. It is these surrounding water supply or gas communications routes that we are used to seeing. The round cross section of the pipeline is characterized by better conductivity with a minimum surface size.
But not in all conditions the pipe of round section works best. For example, it bends easier, which is good for the construction of integral turns of the water supply, but quite unfavorable for the rigidity of the hinged structures. Profile pipes have completely different advantages and characteristics.
Profile pipe is a hollow pipe-rolling product, which has any intersection, except round. Usually, in section we see an oval, square or rectangle, although today rolling technology makes it possible to produce more complex geometry.
In terms of physical parameters, flat-oval pipes are almost indistinguishable from round ones, but they are highly decorative, therefore, they are often used for the design of buildings, creation of fence elements, furniture. Another point is the large surface area of the outer area with a significant reduction in interior space, which allows to use the oval pipeline effectively in cooling systems, where the maximum heat output from the carrier is required. exept this, oval profile is characterized by high, therefore it is also called "arched".
Rectangular and square pipes perfectly withstand transverse loads, because of this they are used to create various elements of furniture and building load-bearing systems. Frameworks of architectural buildings are constructed from closed profiles, make columns, racks, floor beams. Profile pipes are required for reinforcement of metal-plastic windows, for assembly of apertures and cloths of steel doors.
A method of manufacturing profile pipes
Production of profiles of rectangular section of pipes is similarly round. On pipe welding machines, sheet blanks are bent into a cylinder, and the resulting seam is brewed. After the round pipe is passed through a system of rolls, in which it is compressed to hundreds of tons to the desired cross section. Then the profile product is heated, to "release" strained metal after pressure.
With that in mind, whether the workpiece is heated during rolling, pipes are divided into hot-rolled and cold-rolled. Then the geometry of the profile and the quality of the seam are checked, products are cut to size and stored. Consumer pipes are shipped in bundles weighing up to 5 tons. To protect the product can be treated with oil and packed in steel boxes.
Not always the closed profile is made of an electric welding pipe. There are also profile seamless products, their rolling is obtained on calibration rolls from a continuous tube of round cross section. The solid pipe has no seam, it is made of an integral cylindrical workpiece. Seamless profile section is characterized by increased tightness and stability, but it is much more expensive.
Design characteristics and manufacturing process of oval pipes are specified in GOST-8642 68. Square pipes are made, taking into account GOST 8639 82, GOST-30245 2003, for rectangular products use GOST-30245 2003 and GOST 8645 68. These rules contain:
-
wall thickness;
- geometric dimensions of the section;
- rounding radius;
- weight per running meter;
- determine the quality of defects and their maximum tolerances;
- length of products;
- labeling rules;
- resistance to mechanical stress.
That is, if you need to buy a batch of rolled products for high quality products, the range and conformity of the GOST pipe can be checked without problems by means of the measuring device.
The main advantages of profile pipes
Naturally, the main advantage of a square or rectangular profiled pipe is its considerable spatial rigidity, unlike products of round section. Since this is a closed profile with four stiffeners. If the professional pipe is used as a load-bearing beam, and the load is at an angle 90 degrees to the plane, then the resistance of the profile to the bend will be approximately 35% more, than the analogue of the round section.
This figure is close to the parameters of a solid steel rod. If the force vector is predetermined, then instead of a square you can choose a rectangular cross section, setting a long part of the profile on the impact vector. The use of a rectangular pipe reduces the material consumption of the pipe by about 25%.
Due to the flat surfaces, rectangular and square pipes are much easier to handle. They are easier to prime and paint, protective coatings are better retained on surfaces. These are metal products, for example, unlike a channel or an I-beam, has no hard-to-reach places for processing, which has a positive effect on corrosion resistance.
Flat edges provide good ergonomics. These profiles are firmly connected to any structural elements, they are quite convenient to lay on load-bearing surfaces. Profile pipes take up a minimum amount of space at the base, without creating dead zones. They are easier to screw, they are easier to line with sheet materials.
The presence of planes provides the products with good stability during transportation and storage, they can be packed in rectangular bundles. At the same time round pipes, Moreover, large diameter, due to the possibility of moving are considered a source of high danger - loaded and delivered by special vehicles and stacked only "pyramid".
How to choose the right profile pipe
In order for the metal to have sufficient durability and design performance, you need to carefully choose the type of profile pipe. There are many criteria, and each reflects certain properties of the product.
Method of manufacture
Taking into account the peculiarities of the technological process of manufacturing profile products are divided into:
- Seamless;
- Welded;
- Cold rolled;
- Hot rolled.
Hot-rolled pipes are general and construction products, they are used to create external metal structures, for construction of bearing frameworks and building support. They, due to the processing of workpieces under high temperature, characterized by low surface roughness, but do not have internal stresses. This technology gives the chance to make professional pipes of big diameter with the increased thickness of walls. Since high-carbon and alloy steel is easier to deform at elevated temperatures, CC pipes often have anti-corrosion properties..
Cold rolling makes it possible to make high quality profiles. This applies to the accuracy of geometric dimensions and surface cleanliness. This type of product is chosen to create structures, to which high requirements of operation are put forward. Deformation of the workpiece without the use of elevated temperatures makes this profile more resistant to internal or external pressure, and it is better amenable to bending.
Seamless pipes have much greater strength, than electric welded, because a poor quality seam can be a weakness. exept this, seamless hot-deformed pipes, usually, are made with the increased thickness of a wall - more than one centimeter. Seamless products are characterized by good surface quality, elasticity, resistance to high pressure.
Material of manufacture
Proftruby can be made of any carbon steel. Products with a thin coating of a zinc layer have the increased anticorrosive properties, they rust in 7-8 times slower, than ordinary blacks. Galvanizing is by spraying or immersing the profile in a zinc alloy.
Stainless steel professional pipes have almost complete resistance to corrosion, they are made, usually, from steel grades AISI304 and AISI316, a little less often - with AISI439. They are most often used for the construction of architectural elements of the building and less often - for the construction of load-bearing frames. The stainless steel profile is characterized by a variety of finishing options, heat resistance, abrasion resistance.
Rounding corners
This parameter is specified by the current GOST for the manufacture of pipes. The radius of the angle in 2S is optimal (double wall thickness). Taking into account the characteristics of equipment and manufacture, in practice, the radius of rounding corners is often higher than the design, this allows the manufacturer to make products cheaper and easier. Products with very small roundings look more beautiful, but they are more expensive and heavier than standard ones. It should be noted, that autumn round and too right angles reduce the structure bearing characteristics.
The thickness of the walls
The division of the pipes according to the thickness of the walls is a rather conditional criterion. Here you need to take into account the ratio of the outer diameter to the thickness of the outer wall. The pipe is thin-walled, when this ratio does not exceed the limit 0,025, at a ratio of 0,05 - the profile is called standard, thick-walled pipe has larger proportions 0,1 v. In any case, the technology is as follows, that the larger the diameter of the product - the thicker the walls.
GOST clearly defines, what are the possibilities of this ratio are possible with a certain method of manufacture. Example, square profile with side 190 millimeters and wall 5-15 millimeters can only be made by hot deformation. The wall thickness of closed products can vary in thickness in the range 2-14 millimeters, certainly, for heavier structures, a profile with thicker walls should be used.
Mechanical characteristics
Classification of professional pipes, taking into account the chemical and mechanical characteristics of the workpiece, can tell about the purpose of the profile. The following designation is used for this type of rectangular metal products:
- A - only mechanical parameters are normalized;
- B - normalized and chemical composition, mechanical indicators.
Usually, rationing of marking "B" is provided for products of large size, therefore, they are often chosen for the construction of load-bearing structures. The products are tested for impact strength at a temperature of -25 to +25. The same test is done after artificial aging of steel. Metal rolling is not subjected to hydraulic tests, but some manufacturers do it on their own initiative, and, naturally, can guarantee normal operation of products at a certain pressure. These profiles are marked "D".
Obviously, that profile rectangular pipe rolling is quite convenient to operate, and a truly universal and indispensable material for construction. It is difficult to underestimate the financial and technological benefits, which are obtained when using a closed profile of rectangular or square cross section.
