Modern ventilation systems are subject to increased requirements. The comfort and safety of people inside the building depend on the quality of its installation. Therefore, before arranging ventilation, engineers make an accurate calculation of its parameters.
Galvanized steel round ducts are most often used for similar purposes in industrial and domestic facilities. This is due to their special characteristics. The attractiveness of such ducts must be considered in more detail.
Duct selection
An air duct is an element of a ventilation system made in the form of a duct. He takes a direct part in the circulation of air masses and their exchange with the environment. This process can occur naturally or forcibly (using compressors).
The efficiency of air exchange depends on the type of pipes, their characteristics. Insufficient diameter or inappropriate material will lead to a decrease in the throughput of communications, the appearance of aerodynamic noise.
Galvanized steel round ducts are used more often than others. This is due to their features and properties. Important parameters of such products are stiffness, cross-sectional diameter, shape, type of material, as well as features of the connections of structural elements.
In order for ventilation pipes to meet modern requirements, they are produced in accordance with GOST 19904-90.
Material characteristic
Round ducts made of galvanized steel, the GOST of which involves their machine or manual production, are now in great demand. They are created from a sheet blank.
Thanks to the use of this kind of galvanized steel, it is possible to achieve low aerodynamic drag. Installation of products is quite simple. The galvanized steel circular duct flange is less commonly used than the nipple.
From thin-sheet blanks, it is possible to make round and rectangular ducts of any section. The service life of products made of this material reaches 10 years. Galvanization is not subject to corrosion. It is easy to transport and install on site.
Varieties
Round ducts made of galvanized steel have several varieties, depending on certain classification criteria.
By the type of weld, the pipes can be spiral-strained or straight-seam. The former are more reliable. Their shape determines the additional stiffness and reliability of the duct.
The class of density and tightness of the material can be P (dense) and H (normal). In the first case, the products withstand a pressure of 1.4 kPa. They are allowed to be installed in rooms that are characterized by an increased fire or explosion hazard. In ordinary buildings, class N ducts are used.
Spiral Pipe Production
Galvanized steel spiral ducts are made from a strip of 137 mm wide. It is twisted in a spiral and connected by edges as a lock fastener. Moreover, the seam of such a product is always located outside.
The diameter of the finished duct directly depends on the thickness of the galvanized steel billet. For products with a cross section of 150-350 mm, a material of 0.55 mm is required. If the diameter of the pipe requires 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 should have 1 mm of thickness.
Factory production ensures the supply of 3-6 m pipe materials to the market. If the consumer 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 explained by their characteristics. In the case of manufacturing a spiral seam, circular ducts made of galvanized steel have increased strength. The ribs give rigidity to the structure, and a thin sheet of steel ensures lightness of the product.
The tightness class of pipes of the presented variety P. Joints are additionally treated with silicone sealant.
Due to the listed qualities, the installation of such products is simple and does not require a large number of connections. To equip the ventilation system, it is possible to use pipes up to 12 m long.
The air that passes through such communications is additionally swirling. This gives it acceleration and reduces noise.
Longitudinal pipes and their production
The manufacture of longitudinal ventilation systems involves fixing the edges of a sheet of steel with a nipple or flange.
For standard product sizes, sheet cutting is performed automatically. If there is a need to make galvanized steel ducts with other parameters, the cut is done manually using special equipment.
After cutting, the workpiece falls onto the rollers. They twist the material into a tube of the required diameter. Next, the workpiece falls on a folding mill. The longitudinal edge of the duct is being machined. The folds are upset over the entire length.
In this way, short pipes of 1.5-2.5 m are obtained. For the installation of these products, various shaped products are used.
Advantages of longitudinal pipes
If we compare straight-seam round ducts made of galvanized steel with their rectangular varieties, the first option is cheaper. They are more "quiet", have better aerodynamics. They are easier to install than rectangular ducts.
But when compared with spiral-wound pipes, longitudinal seams are more difficult to install. They need to make more connections, because the length of products of this type is quite small.
Therefore, when arranging ventilation in a private house, longitudinal pipes are used. They are cheaper. But in industrial conditions, spiral-wound ducts are used more often. The fewer connections in the arrangement of the system will be made, the better.
Shaped elements
To carry out a turn, branch or transition, shaped products are made of galvanized steel for round ducts . They can be of different diameters and are selected in accordance with the cross section of the ventilation pipe.
Elements intended for arrangement and full installation of the system include such products: tees, turns, umbrellas, tires, transitions, bends, insets and crosses. It happens that when installing ventilation of complex design, more shaped products are used in total than the pipes themselves.
Therefore, the quality of their production is no less important than ductwork. The fewer connections the system has, the better. At the junctions, dust and debris accumulate over time. Therefore, the smoother the surface inside, the longer the life of the system will be.
Having familiarized yourself with such products as round ducts made of galvanized steel, we can conclude that this is a fairly popular system. Its cost and operational qualities determine their relevance in the installation of various ventilation systems. For each type of room, you need to choose your own kind of pipe.