Engineering duct production and installation process technology analysis

HVAC engineering air duct production and installation process

Duct support bracket production and installation

The basic function of the support bracket is to bear the weight of the air duct and fix the air duct, so keeping the installation firm is the first thing, the construction must be in accordance with the design requirements of the support bracket installed in a suitable position. First of all should be based on the design needs of the construction drawings, select the appropriate type and material, and then according to the requirements of the pipeline support hanger construction process specification, to prepare for the construction of a variety of machinery and equipment needed, will be steel, steel, welding materials, etc. transported to the production site, the implementation of the section of the steel and other materials, inspection and correction, small steel can be taken to the cold correction, and the larger steel needs to be heated to 900 ° after the implementation of the hot correction, and the first correction of twisted, then correction of bending. Correction of distortion, and then correction of bending. Duct support hangers should be carefully prepared before installation, according to the design requirements of the specifications of the support hangers, models, number of good statistics, and in the welding process to control the precision of the processing, the installation can be welded or bolted fixed to the floor, reinforced concrete beams or steel beams, and do a good job of rust, pay attention to the angle of the support hangers and the spacing, the construction workers shall not be greedy for saving time to destroy the original design. Welding work to ensure that the connection parts of the connection on the basis of close, as far as possible to enhance the level of welding technology construction, to avoid leakage of welding, welding bias, weld tumor and other issues, and after welding the weld joints need to be properly processed, to ensure that the appearance of the aesthetics.

 

Duct production and installation

1. Duct production.

According to the specification size of the air duct under the material, galvanized iron bite, steel plate under the material must be corner square, line flat, etc. accurate; air duct requirements negative deviation. Ducts and fittings surface should be flat, uniform arc, longitudinal seams should be staggered; duct splicing using single bite, duct corners using joint bite, bite seam should be tight, uniform width; weld should be checked for appearance, there should be no air holes, trachoma, slag, cracks, and other defects, the deformation of the steel plate after welding should be corrected. Air supply ducts, return ducts and fresh air ducts, are made of galvanized steel plate, the thickness of which is 0.75mm. duct reinforcement: rectangular ducts ≥ 630mm, the length of the section of 1200mm or more, are required to set up reinforcement measures.

2. Duct connection.

Formally put the material into the construction before the duct material to pre-connection, so that construction personnel can be familiar with the construction process, but also timely detection of possible problems in the assembly and connection process, after improvement and qualified, and then according to the construction steps to complete the connection work. Connection process should pay attention to the different properties of different flange connection, such as angle iron flange and flat steel flange need to be specifically designed riveting process and thickness size, flange connection with the nut on the same side, and will be bolts according to the cross symmetrical tightening, connecting the flange gasket used in the air ducts should be used thickness of more than 3mm of the combustion properties and heat-resistant performance in line with the relevant norms of the gasket. Before connecting and installing the air ducts, it is also necessary to check whether there are foreign objects and sundries on the inner wall, and clean the inner wall of the ducts by reasonable means to ensure smoothness and cleanliness. Each section of the duct on both sides with encapsulation, construction workers to remove the polyethylene film during installation.

3、Duct installation.

Before the installation of air ducts, check the size and elevation of the air ducts through the floor and wall holes. Insulation duct to prevent cold bridges in the duct and hangers between the addition of cushion wood, cushion wood thickness with the insulation layer. Used to support the round air duct, the steel boom is not allowed to contact with any part of the air duct. The hanger should keep the space for installation and free expansion and contraction of the air duct. Fresh air inlet and duct shall have a drain pan welded to the bottom, the drain pan shall be coated with heavy asphalt paint, there shall be a drain pipe leading to a nearby floor drain, provide a drain pipe leading from the drain pan, fresh air inlet pipe, and equipment enclosure, and the drain pipe shall consist of No. 40 galvanized steel pipe fittings. Assembled systems are supplied with stainless steel drain pans, cork coated with 50mm Matty's grease to act as cushions for the drain pans, stainless steel drain undercuts and galvanized drain pans and water seals for the multi-stage cold pans on their bases. Insulation hose is installed straight and short, minimum 1.5m, try to use a large radius curvature when bending, when using the hose to connect the two horizontal and vertical direction there is a deviation of the air duct interface, if possible should ensure that the distance between the air duct interface is the sum of the two deviations of three times to ensure that the airflow in the duct to maintain laminar flow movement and the duct interface with the connection of the nibble or hose clamps. When connecting to insulated or acoustically insulated ducts, provide an insulated joint connection.

4. Installation of ventilation components.

The muffler should be installed in the correct direction and should not be damaged or exposed to moisture. The muffler should have a separate bracket to avoid its weight being borne by the air duct. Before installing the fire damper, check whether its model and position are in accordance with the design requirements and whether there is any certificate of conformity of the product; the fusible piece of the fire damper should be installed facing the direction of airflow; in order to prevent the fusible piece from falling off, the fusible piece should be installed after the installation of the system, and the action test should be done after the installation; the fire damper should be installed with separate bracket. Install smoke exhaust valve, smoke vent and hand control device (including pre-buried conduit) according to the position required by the design, and do action test after installation of smoke exhaust valve to check whether its manual and electric operation is sensitive and reliable, and whether the valve body is closed tightly.

When the air outlet is installed, ensure that the air outlet is connected with the air duct tightly and firmly; the frame of the air outlet is affixed to the decorative surface of the building; the external surface of the air outlet after installation is ensured to be smooth and not deformed, and the adjustment is flexible. Prevention of vibration and noise during installation: prevention of vibration and noise is a key point in the installation process.