What matters should we pay attention to in the production of air duct?

The production process of air duct involves many links, and each link has matters needing attention, as follows:

Design link

Accurate measurement: Before construction, the installation site should be measured in detail, including the size of the building and the position of the beam and column, etc., to ensure that the design size of the air duct conforms to the actual situation on site, and to avoid problems such as collision between the air duct and other facilities and inability to install it in the later stage.

Consider the use scenario: different places have different requirements for air ducts. For example, the air duct should have good sealing performance and surface smoothness in places such as hospital operating rooms and food factory workshops that require high air cleanliness to reduce the accumulation of dust and bacteria; In industrial workshops with explosion-proof requirements, such as oil refineries, coal mines and other places, the materials of air ducts should be explosion-proof materials, and the grounding of air duct system should be ensured during installation to prevent explosion accidents caused by static electricity.

Material selection and inspection

Material adaptation: according to the use place, working pressure, conveying medium and other factors of the air duct, choose the appropriate air duct material. Common duct materials include galvanized steel plate, stainless steel plate, aluminum plate and composite duct plate. For example, the general ventilation and air conditioning system can choose galvanized steel duct, which has good mechanical strength and corrosion resistance and relatively low price; For places with acid and alkali corrosion resistance requirements, such as chemical workshops and electroplating workshops, stainless steel plate air ducts or glass fiber reinforced plastic air ducts should be selected.

Strict inspection: when materials enter the site, they should be strictly inspected for their specifications, models, thickness and material certification documents to ensure that the materials meet the design requirements and relevant standards and specifications. At the same time, the material should be visually inspected. For example, the surface of galvanized steel plate should be smooth, without zinc layer falling off and obvious scratches. The internal and external surfaces of composite air duct plates shall be smooth, free from damage and bubbles. Materials that do not meet the requirements shall be resolutely removed from the site, and shall not be used in engineering construction.

Processing and manufacturing

Equipment maintenance and operation specification: Air duct processing equipment, such as shearing machine, folding machine, bite machine, plasma cutting machine, etc., should be maintained regularly to ensure that the equipment is in good running condition. In the process of equipment operation, operators should strictly abide by the operating rules and be familiar with the performance and operation methods of the equipment to avoid equipment damage or safety accidents caused by improper operation. For example, when using the plate shearing machine to shear plates, the blade gap and shearing angle of the plate shearing machine should be reasonably adjusted according to the thickness and material of the plate, and at the same time, the plate should be placed smoothly during the shearing process to avoid the plate from being offset or tilted, which will affect the shearing quality and operation safety.

Machining accuracy control: the machining size of the air duct should be strictly controlled according to the requirements of the design drawings to ensure that the dimensional deviation of the length, width and height of the air duct is within the allowable range. In the bite connection and flange connection of the air duct, the tightness and firmness of the connection should be ensured to avoid air leakage. For example, in the process of air duct bite processing, it is necessary to control the width and depth of the bite to ensure the quality of the bite meets the requirements; In the process of connecting the air duct with the flange, it is necessary to ensure the verticality between the flange and the air duct, as well as the position accuracy of the bolt holes, so as to ensure the overall structure stability and good sealing of the connected air duct system.

Protection of semi-finished products: In the process of manufacturing air ducts, effective protection measures should be taken for semi-finished air ducts that have been processed to prevent them from being damaged, deformed or polluted. For example, in the storage process of semi-finished air duct, it should be placed in a flat, dry place, and the air duct should be raised with skids or other supports to prevent the air duct from being rusted by moisture or scratched by ground debris due to direct contact with the ground; At the same time, the storage site should be properly fenced and covered to prevent external factors from damaging the semi-finished air duct. In the handling process of semi-finished air ducts, appropriate handling tools and methods should be adopted, such as forklifts, cranes and other equipment, and the air ducts should be reasonably bound and fixed during the handling process to prevent the air ducts from being damaged due to collision and sliding during the handling process.

Transportation and installation

Transportation protection: In the process of air duct transportation, due to the bumping and turning of vehicles, it is easy to cause the air ducts to collide and squeeze each other, thus causing the deformation and damage of the air ducts. Therefore, when loading the air duct, the position of the air duct should be arranged reasonably according to the size, shape and weight of the air duct, so as to make the center of gravity of the air duct evenly distributed as far as possible and avoid the air duct from dumping during transportation due to the deviation of the center of gravity. At the same time, sufficient cushioning materials, such as foam board and rubber pad, should be set between the air ducts to reduce the impact force when the air ducts collide with each other; It is also necessary to firmly bind and fix the air duct with ropes and steel belts to ensure that the air duct will not move or slide during transportation.

Installation sequence and coordination: the installation of air ducts should be carried out in a reasonable order, generally, the main pipe should be installed first, and then the branch pipe should be installed; Install the high air duct first, and then install the low air duct. In the installation process, we should pay attention to the coordination with other professional types of work, such as keeping close communication with the construction personnel of electrical, fire protection, water supply and drainage and other professions, solving various problems in the construction process in time, and avoiding the decline of engineering quality and construction schedule delay caused by unreasonable or mutual interference of various professions.

Connection, sealing and reinforcement: the connection part of the air duct is the key link to ensure the sealing and stability of the air duct system. When the air duct is connected, the appropriate sealing materials and connectors should be selected according to the material, specification and connection mode of the air duct to ensure good sealing performance and firm and reliable connection. For example, in the flange connection of galvanized steel duct, sealing materials such as rubber plate and asbestos rubber plate with a thickness of 3-5mm should be padded between flanges, and the flanges should be closely connected with bolts, and the tightening degree of bolts should be moderate, so as to ensure the tightness of flange connection and avoid flange deformation or damage of sealing materials caused by over-tightening bolts; For large-diameter air duct or high-pressure air duct system, in order to enhance the strength and stability of the air duct, it is necessary to reinforce the air duct. The common reinforcement methods include rib reinforcement, vertical reinforcement, angle steel reinforcement, flat steel reinforcement, etc. The specific reinforcement methods should be reasonably selected according to the size, pressure grade and use requirements of the air duct.

Quality inspection and acceptance

Process inspection: strict quality inspection should be carried out in all aspects of duct production, including material inspection, processing, transportation and installation. Quality inspectors should be familiar with the relevant quality standards and inspection methods, and use various means such as visual inspection, ruler measurement, weighing, and testing instruments to conduct a comprehensive inspection on the dimension deviation, appearance quality, tightness of connection parts, strength and stability of the air duct. For the quality problems found in the inspection process, it is necessary to timely record and notify the relevant responsible person to make rectification, and conduct a review after the rectification is completed to ensure that the quality problems are completely solved and prevent unqualified products from entering the next process or being delivered for use.