How to carry out anti-corrosion and heat insulation design in the construction of ventilation and air conditioning works in clean rooms? Ed purification will give you a detailed understanding of:
10.1 general provisions
10.1.1 the heat insulation engineering construction of air duct, components and air conditioning equipment in the clean room shall be carried out after the air duct system passes the tightness inspection.
Note: 10.1.1 this article specifies the preconditions for the construction of heat insulation works of air ducts, components and air conditioning equipment, which can only be carried out after the air duct system passes the tightness inspection. Tightness inspection of air duct system refers to light leakage detection or air leakage measurement of air duct system.
10.1.2 the construction of the refrigeration system pipeline of the clean room air conditioning project, including the insulation project of the refrigerant and air conditioning water system, shall be carried out after the strength and tightness inspection of the pipeline system are qualified and the anti-corrosion treatment is completed.
Note: 10.1.2 this article specifies the construction conditions of heat insulation for air conditioning refrigerant pipeline and air conditioning water system pipeline. The heat insulation construction of pipeline is the next process of pipeline installation engineering, which can only be carried out after the current process is completed and verified to be qualified.
10.1.3 before making air duct, ordinary steel sheet should be pre coated with one coat of antirust paint.
Note: 10.1.3 two methods can be adopted for anti-corrosion treatment of common thin steel plate air duct, i.e. processing and forming before painting anti-corrosion paint and processing and forming after painting anti-corrosion paint. Compared with the two methods, the latter has higher construction efficiency and better anti-corrosion effect on the undercut joint and flange riveting joint. In order to improve the anti-corrosion performance of the air duct and guarantee the engineering quality, this regulation is hereby formulated.
10.1.4 the anti-corrosion treatment of supports and hangers shall be consistent with that of air pipes or pipes, and the exposed parts must be coated with finish paint.
Note: 10.1.4 in general, supports and hangers are made of ferrous materials and in the same environment as air ducts or pipes. Therefore, their anti-corrosion treatment should be consistent with the air pipe or pipeline. In some buildings, there are acid, alkali or other corrosive plants. When PVC, FRP or stainless steel plates (pipes) are used for air pipes or pipes, the anti-corrosion treatment of supports and hangers shall be the same as the anti-corrosion performance of air pipes and pipes or in accordance with the design provisions.
Paint can be divided into primer and finish. The primer is mainly adhesive and anti rust. The top coat is mainly used to protect primers, increase anti-aging performance and adjust surface color. If the supports and hangers of the non concealed exposed parts are not painted with the top coat, the anticorrosive primer will quickly age and fail, which is not beautiful.
10.1.5 during the paint construction, measures such as fire prevention, antifreeze and rain protection shall be taken, and the operation shall not be carried out in low temperature or humid environment. The last coat of color paint for exposed parts should be carried out after installation.
Note: 10.1.5 during the paint construction, measures such as fire prevention, antifreeze and rainproof shall be taken, which is the basic requirement of general paint engineering construction. However, some operators do not pay attention to this work, which will not only affect the quality of paint, but also may cause fire accidents. In addition, most of the paint at low temperature (usually below 5 ℃) viscosity increases, painting is not easy to carry out, resulting in uneven thickness, not easy to dry and other defects, affecting the anti-corrosion effect. If anti-corrosion construction is carried out in humid environment (generally referring to relative humidity greater than 85%), due to a certain amount of water vapor accumulated on the metal surface, it is easy to reduce the adhesion ability of the film and generate pores, etc., so this regulation is made.
10.2 main control items
10.2.1 the heat insulation of air duct and pipeline shall be 1. The heat insulation of air duct and pipeline shall be non combustible or non combustible materials, and its material, density, specification and thickness shall meet the design requirements. If flame-retardant materials are used, their flame-retardant properties shall be checked and they can only be used after they are qualified.
Inspection quantity: randomly check one by batch.
Inspection method: observe and inspect the material certificate, and conduct ignition test.
Note: 10.2.1 this article specifies that the thermal insulation materials used for air ducts and pipes of air conditioning engineering system must be non combustible or non combustible materials, and shall not be combustible materials. From the point of view of fire protection, non combustible materials shall be used as far as possible. However, compared with the application effect, performance and other conditions of heat insulation, the refractory material has its relative advantages and occupies a certain proportion in the project. Flame retardant materials are generally made of inflammable materials as base materials, which are added with flame retardant or dip coated with flame retardant materials. Their appearance is not different from that of flammable materials, so they are easy to be confused. No matter at home or abroad, the heat insulation materials have been ignited in the air conditioning engineering, resulting in bad results. For this reason, the article clearly stipulates that when the engineering thermal insulation material is a fire-resistant material, its fire-resistant performance must be verified and qualified before use.
10.2.2 anticorrosive coating and paint must be qualified products within the validity period.
Inspection quantity: batch inspection.
Inspection method: observe and inspect the material certificate.

Note: 10.2.2 anticorrosive coating and paint have a certain period of validity, and their performance will change greatly after the period. Of course, expired and unqualified products shall not be used in the air conditioning equipment engineering of clean room construction.

10.2.3 incombustible thermal insulation materials must be used in the following situations:
1. 800 mm air duct and thermal insulation layer in front and behind the electric heater;
2. Cross the air duct, pipeline and thermal insulation layer within 2m on both sides of the fire wall.
Inspection quantity: full inspection.
Inspection method: observe and inspect the material certificate and conduct ignition test.
Note: 10.2.3 this article stipulates that the thermal insulation material of air duct within 800mm before and after the electric heater and 2m at both sides of the firewall must be non combustible. This is mainly to prevent the electric heater may cause the spontaneous combustion of the thermal insulation material and prevent the fire in the adjacent room from passing through the passage of the air pipe or pipeline thermal insulation material.
10.2.4 when non closed cell thermal insulation material is used for the pipeline whose transmission medium temperature is lower than the dew point temperature of surrounding air, the vapor barrier (moisture barrier) must be complete and well sealed.
Inspection quantity: spot check 10% according to the quantity, and no less than 5 sections.
Inspection method: observation and inspection.
Note: 10.2.4 this article specifies that when through-hole thermal insulation materials are used for the pipes of air conditioning refrigerant water system, the vapor barrier (moisture barrier) must be complete and sealed. The through-hole thermal insulation material is composed of loose fiber material and air layer, and it is a bad conductor when air is hot. The combination of the two constitutes a good thermal insulation performance. The premise of this performance is that the air layer is required to be static or flow very slowly. Therefore, when the through-hole thermal insulation material is used as the thermal insulation material, the outer surface must be provided with a vapor barrier (moisture barrier), which shall be complete and well sealed. When it is used in the pipeline where the temperature of the conveying medium is lower than the dew point of the surrounding air, the opening of the vapor barrier will produce convection with the air in the inner layer of the thermal insulation material, and the water vapor in the air will be condensed and separated out when encountering the supercooled pipeline. The generation of condensed water will further reduce the thermal resistance of the material, accelerate the convection of air, and eventually lead to the failure of the insulation layer with the delay of time.
10.2.5 for the heat insulation of air ducts and pipes in the clean room, materials that are easy to produce dust (such as glass fiber, short fiber mineral wool, etc.) shall not be used.
Inspection quantity: full inspection.
Inspection method: observation and inspection.
Note: 10.2.5 the main object of clean room control is the amount of floating dust in the air. If the insulation materials of indoor air ducts and pipes are made of materials that are easy to produce dust (such as glass fiber, short fiber mineral wool, etc.), it is obviously not conducive to the clean room. Therefore, it is stipulated in the article that materials easy to produce dust shall not be used.
10.3 general items
10.3.1 the paint film to be sprayed and painted shall be uniform and free from defects such as accumulation, wrinkles, bubbles, dopants, color mixing and missing coating.
Inspection quantity: 10% by area
Inspection method: observation and inspection.
Note: 10.3.1 this article only specifies the basic quality requirements for the paint construction quality of air conditioning engineering.
10.3.2 the paint spraying and coating of all kinds of air conditioning equipment and components shall not cover the nameplate mark and affect the functional use of components.
Inspection quantity: 10% by quantity, and no less than 2.
Inspection method: observation and inspection.
Note: 10.3.2 in the construction of air conditioning works, some air conditioning equipment or parts of air ducts and pipes need to be repaired or repainted with paint. In operation, the failure to pay attention to the protection of equipment signs and the protection of rotating shafts and moving surfaces of blades, such as tuyeres, will cause problems such as illegibility of signs or blade adhesion affecting normal use. Therefore, this article provides.
10.3.3 the thermal insulation of air duct system components shall not affect its operation function.
Inspection quantity: 10% by quantity and no less than 2.
Inspection method: observation and inspection.
Note: 10.3.3 this article only specifies the basic quality requirements for heat insulation construction of air duct components.