What matters should be paid attention to during the construction and installation of stainless steel ventilation pipes?

During the construction and installation of stainless steel ventilation pipeline, there are matters needing attention in pipeline processing, installation, connection and system debugging, as follows:

Pipeline processing

Cutting: Use professional cutting equipment, such as plasma cutting machine and laser cutting machine, to ensure that the cutting surface is smooth and free of burrs, cracks and other defects, so as to avoid affecting the subsequent welding and installation quality.

Bending: When cold bending or hot bending process is adopted, the bending radius and angle should be well controlled to prevent the pipeline from being excessively deformed or wrinkled. For large-diameter pipes, a special pipe bender can be used, and supports or dies can be added as needed to ensure the roundness and wall thickness uniformity of the bending parts.

Welding: Welding personnel should have professional qualifications and adopt appropriate welding technology and parameters, such as argon arc welding. Before welding, the pipeline interface should be cleaned to remove impurities such as oil stain and rust. During welding, the weld should be full and uniform, and there should be no defects such as air holes and slag inclusion. After welding, the welding slag and spatter should be cleaned in time, and the weld should be nondestructive tested.

piping erection

Setting of supports and hangers: Set supports and hangers reasonably according to the weight, size and installation position of the pipeline. The spacing between supports and hangers should meet the design requirements. Generally speaking, for pipes with smaller diameters, the spacing can be appropriately smaller. For large diameter pipes, the spacing should be increased accordingly. The supports and hangers shall be installed firmly and in close contact with the pipeline, and shall not be loose or shaken, and attention shall be paid to prevent the supports and hangers from affecting the thermal expansion and contraction of the pipeline.

Pipeline layout: carry out pipeline layout according to the design drawings, and pay attention to the slope and direction of the pipeline. Generally, the slope of ventilation pipes should be not less than 0.003, and the slope direction should be conducive to the discharge of condensed water. At the same time, it is necessary to avoid mutual interference between the pipeline and other equipment or pipelines, and ensure that there is enough space around the pipeline for maintenance and overhaul.

Crossing the wall and floor: When the pipeline crosses the wall or floor, the casing shall be set. The inner diameter of the casing should be 10-20mm larger than the outer diameter of the pipeline, and the gap between the casing and the pipeline should be filled with incombustible materials to prevent the smoke from spreading through the gap in case of fire. When crossing the parts with waterproof requirements, waterproof treatment should also be done, such as setting a water stop ring around the casing.

Pipe connection

Flange connection: During flange connection, make sure that the flange surface is flat and free from deformation, and the bolt hole position is accurate. When installing the flange gasket, the appropriate material and thickness should be selected to ensure that the gasket is evenly compressed without leakage. When tightening bolts, they should be carried out in a symmetrical and intersecting order to make the flange connection tight.

Welding connection: In addition to ensuring the welding quality, we should also pay attention to the concentricity and straightness of the welded pipeline. For long pipelines, the method of subsection welding and gradual correction can be adopted to reduce the influence of welding deformation on pipeline installation quality.

Flexible connection: Flexible connection, such as canvas soft connection or rubber soft connection, should be adopted at the connection between pipeline and fan, air conditioning unit and other equipment. The length of flexible connection is generally 150-300mm, which is used to reduce the vibration and noise transmission when the equipment is running, and at the same time, it is convenient for the installation and adjustment of the pipeline.

system debug

Air leakage detection: after the installation is completed, air leakage detection should be carried out on the ventilation pipeline system. Light leakage method or air leakage test method can be used to check whether there is air leakage in the weld, flange joint and flexible joint of the pipeline. If air leakage is found, it should be repaired or replaced in time.

Air volume balance debugging: by adjusting the speed of the fan and the opening of the valve, the air volume of each branch pipe of the ventilation system is debugged to achieve the air volume distribution required by the design. During the debugging process, professional air volume measuring instruments, such as anemometer and air volume hood, should be used to accurately measure and adjust the air volume of each tuyere.

Commissioning of equipment operation: check the operation status of fans, air conditioning units and other equipment, including whether the parameters such as speed, vibration, noise and temperature of the equipment are normal. At the same time, observe whether there are problems such as looseness and air leakage at the connection part between the equipment and the pipeline. If there are any abnormalities, stop the machine in time to check and troubleshoot.