Round air ducts made of galvanized steel: GOST, application

To modern ventilation systems are imposedincreased requirements. The quality of its installation depends on the comfort and safety of people inside the building. Therefore, before ventilation is arranged, engineers make an accurate calculation of its parameters.

Round air ducts made of galvanized steel more oftenall are used for similar purposes in industrial and domestic facilities. This is due to their specific characteristics. The more attractive such air ducts, it is necessary to consider in more detail.

Choice of duct

The air duct is an element of the ventilation system,made in the form of a box. It takes a direct part in the circulation of air masses and their exchange with the external environment. This process can occur naturally or compulsorily (with the help of compressors).

The efficiency of air exchange depends on the type of pipes,their characteristics. Inadequate diameter or inadequate material will lead to a decrease in the capacity of communications, the appearance of aerodynamic noise.

Round ducts made of galvanized steelmore often than others. This is due to their features and properties. Important parameters of such products are stiffness, diameter of a section, shape, type of material, and also features of connections of structural elements.

That ventilating pipes corresponded to modern requirements, them make accordingly to GOST 19904-90.

Characteristics of the material

Air ducts of circular cross-section from galvanized steel, GOST of which presupposes their machine or manual production, are now in great demand. They are made from a thin sheet.

Thanks to the application of such a varietyGalvanized steel can achieve low aerodynamic resistance. The installation of the products is quite simple. A flange for a round duct of galvanized steel is used less often than a nipple.

From thin-sheeted workpiece it is possible to carry outAir ducts of round and rectangular shape of any section. The life of products from this material reaches 10 years. Galvanizing is not subject to corrosion. It is easy to transport and install on site.

Varieties

Round ducts made of galvanized steel have several variations, depending on certain characteristics of the classification.

According to the type of weld, the pipes can be spiral wound or straight. The first are more reliable. Their shape causes additional rigidity and reliability of the duct.

The density and tightness class of the material canbe n (dense) and H (normal). In the first case, the products can withstand a pressure of 1.4 kPa. They may be installed in rooms that are characterized by an increased fire or explosion hazard. In conventional buildings, air ducts of class N are used.

Manufacture of spiral-wound pipes

Spiral air ducts made of galvanized steelsteel is made of a strip with a width of 137 mm. It is twisted in a spiral and is joined by edges like a lock fastener. At the same time, the seam of such a product is always outside.

The diameter of the finished air duct is directly dependent onthickness of galvanized steel billet. For products with a cross section of 150-350 mm, a material of 0.55 mm is required. If the pipe diameter is required 360-800 mm, the thickness of the steel for its manufacture should be 0.7 mm. The widest section of ventilation communications is 850-1250 mm. The galvanized sheet must be 1 mm thick.

Factory production provides supplies forthe market of pipe materials is 3-6 m long. If the customer needs to mount the system using a different length of duct, the products are made to order.

Properties of spiral-wound pipes

The popularity of the presented products is explainedtheir characteristics. In the case of a spiral weld, round ducts made of galvanized steel have increased strength. Ribs give the structure rigidity, and a thin sheet of steel ensures the ease of the product.

The tightness class of the pipes of the presented variety P. The joints are additionally treated with a silicone sealant.

Thanks to the listed qualities, the installation of such products is simple and does not require a large number of connections. For equipping the ventilation system, it is possible to use pipes up to 12 m long.

The air that passes through such communications is additionally twisted. This gives it acceleration and reduces noise.

Straight pipes and their manufacture

The manufacture of a single-seam ventilation system involves fastening the edges of a sheet of steel using a nipple or flange.

For standard sizes, cut sheet productsis performed automatically. If there is a need to fabricate air ducts from galvanized steel with other parameters, the cut is made manually with the help of special equipment.

After cutting, the workpiece falls on the rollers. They twist the material into a tube of the required diameter. Then the workpiece falls on the folding mill. The longitudinal edge of the duct is machined. Folds are deposited along the entire length.

This method produces short pipes 1.5-2.5 m. For the installation of these products use a variety of shaped products.

Advantages of straight pipe

If we compare straight-end round ductsof galvanized steel with their rectangular varieties, the first option is cheaper. They are more "quiet", have better aerodynamics. They are easier to assemble than rectangular types of air ducts.

But if we compare it with spiral-wound pipes, the lateral varieties are more difficult to install. For them it is required to make more connections, since the length of products of this type is rather small.

Therefore, when ventilating in a privatethe house uses a straight pipe. They are cheaper. But in industrial conditions spiral airways are used more often. The fewer connections in the arrangement of the system will be done, the better.

Shaped elements

To make a turn, a branch ortransition, from galvanized steel for round ducts produce shaped products. They can be of different diameters and are selected according to the section of the pipe for ventilation.

To the elements intended for arrangement andcomplete installation of the system, such products include tees, turns, umbrellas, tires, transitions, bends, tie-ins and crossings. It happens, when installing ventilation of a complex design, the total amount of shaped products is more than the pipes themselves.

Therefore, the quality of their production is no less important,than air ducts. The fewer connections the system has, the better. Over time, dust and debris accumulate. Therefore, the smoother the surface inside, the longer the life of the system will be.

Having familiarized with such products as roundair ducts made of galvanized steel, we can conclude that this is a fairly popular system. Its cost and operational qualities stipulate their relevance for the installation of various ventilation systems. For each type of room you need to choose your own type of pipe.