Manufacturing and installation technology of ventilation pipeline?

What is the specific content of ventilation pipe manufacturing and installation technology? Zhong Da Consulting will answer your questions below.

(a), indoor metal duct construction technology

1, material requirements

A, plate surface should be smooth, the thickness should be uniform, no obvious concave-convex rolling phenomenon, can not have cracks, sand holes, scars, burrs and corrosion, and so on and so forth.

B the thickness of the selected material shall meet the requirements of the specification: (mm)

C-beam should be uniform, and there should be no cracks, bubbles, holes and other defects that affect the quality. It should be noted that the existing angle steel has unequal sides.

2. Operating conditions of air duct production

1, the drawings have been familiar with and passed the blue prints.the design. There have been solutions to the problems in the drawings of buildings, structures, electricity, heating and sanitation, such as pipeline direction, coordinates, elevation and ventilation pipeline intersection.

2. All oil stains on the surface of the material should be removed to avoid local corrosion caused by rust or oxide falling on the surface of the material.

3. There must be a separate processing site. In order not to damage the protective film outside the galvanized steel plate, it is best to lay a wooden board or rubber board in the workplace to keep the site clean.

4. The construction technical disclosure was carried out, and the size, technical standard, interface and flange connection mode of the air duct were defined. And make construction disclosure records.

1), air duct processing

According to the size of the long side of the air duct, choose the appropriate material. According to the correct lofting production.

When flanging the air duct, a flanging allowance of not less than 6mm shall be reserved, the flanging shall not cover the bolt hole, the undercut shall be chamfered or chamfered with scissors, and it shall not crack to form an arc flanging. If there are cracks in the four corners of the flanging, it should be filled with solder or sealant to prevent air leakage in the air duct. When the thickness of air duct plate is less than 1.2mm, joint angle or bite can be adopted, and when it is greater than 1.2mm, welding can be adopted.

After the duct is formed, it will be riveted with the flange, with the distance between the rivet and the pipe wall not more than 50mm and the rivet spacing not more than150 mm. ..

When the long side of rectangular air duct is greater than 630mm (insulation air duct is greater than 800mm), the long side size is greater than 1250mm, or the unilateral area of low pressure air duct is greater than 1.2m2, and the medium and high pressure air duct is greater than 1.0m2, reinforcement measures must be taken. ..

When the diameter of circular air duct (excluding spiral duct) is greater than or equal to 800mm, and its section length is greater than 1250mm or its total surface area is greater than 4m2, reinforcement measures must be taken.

The side length of the air duct is ≥630mm, and L is ≥ 1 250 mm. The angle steel of the reinforced frame of the non-thermal insulation air duct is smaller than the flange angle steel1.

3) Installation of air ducts and components

A the detachable interfaces and regulating valves of air ducts and accessories shall not be installed on walls or floors. Ventilation hose

Before installation, internal and external sundries and dirt should be removed and kept clean.

The horizontal and vertical air ducts installed against the wall or column shall adopt cantilever supports or diagonal supports. Horizontal air ducts not installed against walls or columns should adopt bottom hangers, vertical air ducts should adopt hoop brackets, air ducts with a size of B > 800 mm should be provided with double nuts, and anti-sway brackets should be set at corners, tops and ends. Brackets shall not be set at tuyeres, valves, inspection holes and automatic control mechanisms. Hangers should not be directly fixed on flanges.

Rectangular duct hoop bracket should be close to the duct. For example, air duct insulation, air duct hangers of asphalt-impregnated wood blocks should be straight, the threads should be smooth, and the hangers can be welded. The length should not be less than 6 times the diameter of the boom, and should be welded on both sides.

Grasp the following points in construction quality control management:

Making plates with air ducts and profiles with flanges should meet the specifications and design requirements.

The process quality of duct fabrication and component fabrication should meet the requirements.

Protection of finished pipe

The air duct interface shall not be installed on the wall or floor, and the air valve components connected with the air duct shall be separately supported and fixed.

Duct connection should be tight, flanges should not be misplaced, and sliding connection should be firm and tight.

After installation, the air duct layout should be beautiful, and the bracket and air duct should not be tilted.

2), cutting and bending:

A, check whether the lofting of air duct plate meets the requirements of air duct production task list, whether the marking is correct and whether the plate is damaged. Check whether the blade is installed securely. Check whether the protruding height of the blade meets the requirements.

B, straight line according to the requirements of trimming choose left 45 single-edged planer or right 45 single-edged planer. Put the plate on the workbench and fix the aluminum alloy ruler in a suitable position in parallel.

C. During oblique cutting, the blade of the cutter is required to be inclined 45 to the left or right during installation, so that the V-shaped cut is 90, which is convenient for right-angle folding. When cutting, the cutter should insist on using the guide rule to ensure that the incision is straight and prevent the cutting size error.

D, after the plate is cut into a single duct board, the duct boards shall be numbered to prevent the duct boards of different ducts from making mistakes.

E, pressure air duct surface, pressure spacing is generally between 30 ~ 70 cm, pressure depth should not exceed 5 mm ... Bend the metal plate by bending.

3) Forming:

A. Brush the adhesive on the cutting surface of the plate with a brush. When the glue does not touch hands, the air duct panel should be designed as required.

Seek adhesion and flatten with a scraper.

B, check whether the joint bonding meets the quality standards, and mark the section.

4), steel bar:

A, there are two ways to reinforce the air duct. One is corner reinforcement, and the other is plane reinforcement. When the duct edge is longer than > 400mm, plane reinforcement is adopted; Angle steel shall be used for reinforcement when the side length of 250≤ 400 mm.

B, plane steel bar is to use grinding wheel cutting machine to cut off the side length of steel bar supporting steel duct as required, and cut off DN 15 galvanized pipe. On both ends of galvanized pipe, put 60mm long logs. Fix logs on both ends of galvanized pipe with clips.

According to the design requirements, use a steel ruler to determine the reinforcement points on the surface of the air duct.

C, duct angle reinforcement is to paste galvanized right-angle gaskets with a thickness greater than 0.75mm on the four corners of the duct. The width of the right-angle gasket is equal to the thickness of the air duct plate, and the side length is not less than 55 mm ..

5), duct connection:

A, when selecting PVC and aluminum alloy molded connectors, attention should be paid to the wall thickness of connectors, the wall thickness of plug-in flanges should be greater than or equal to 1.5mm, the tube plate thickness and flange groove width should have an interference of 0. 1 mm ~ 0.5 mm, and the plug-in surfaces should be coated with adhesive;

B, the main air duct can be directly connected with the branch air duct at the four corners with 90 joints or other special joints;

Sealants should be used. When connecting the main air duct with the flexible air duct, pay attention to push the annular stop onto the composite plate, and then draw the edge and fix it.

6), duct hoisting:

A, according to the system number and tag for installation; Check whether the air duct size and flange installation at the installation site are correct; Whether the allowable deviation of duct and flange fabrication meets the requirements; Before installation, dust on the inner and outer surfaces of the air duct and sundries in the duct should be removed.

B lift the air duct, install the cross arm and shock pad under the air duct, and fix the cross arm with flat pad, spring pad and nut.

C, according to the design requirements, install the components connecting the air duct and the ventilation system, and conduct heat insulation treatment on the metal flange and the metal ventilation components.

Grasp the following points in construction quality control management.

1. In order to ensure the strength of the air duct after production, 20mm aluminum foil should be reserved on one side of the bonding place when blanking;

2, duct should be pre-assembled before bonding, check whether flat-fell seam is tight, size is in line with the requirements. According to the season;

The optimum bonding time is determined by saving temperature, humidity and the properties of adhesive. After bonding, check and adjust verticality and diagonal deviation with a square ruler and steel tape measure.

3. Do a good job in the protection of finished products of on-site plates and prefabricated pipes;

4. After the connection is installed, check the bonding condition of the bonded joint. After bonding, it should be smooth, and there should be no defects such as skew, dislocation, local cracking and cracks over 2mm.

5. The spacing between supports and hangers of air duct shall comply with the regulations.

(2), duct insulation construction

1, pipeline insulation conditions

1), confirm that the construction of pipeline, electrical, fire protection and other specialties above the air duct has basically ended, so as to avoid a large number of cross operations from damaging the thermal insulation.

2), duct system installed, self-inspection quality is qualified, and to the supervision of inspection, take cover engineering inspection records.

3) Air leakage and light transmission of air conditioning system are qualified.

2, process requirements

1), and select thermal insulation materials according to the design or specification requirements.

2), blanking should be accurate. The cutting surface should be flush. When cutting materials, the short surface and both ends should be placed on the girder at the overlap of horizontal and vertical planes.

3) The coating thickness shall be uniform and shall not be piled up or flowed. Thermal insulation materials shall be covered and bonded tightly, and there shall be no empty drum, and the joints shall be tight and bare.

3, rubber sponge insulation process

1), first wipe the surface of the air duct clean, wipe off the dust and water on the surface, and dry it.

2), according to the size of the duct cutting heat preservation material, according to the provisions of the long side pressure short side blanking.

3) Apply glue evenly on the outer wall of the pipeline and the rubber sponge board respectively, and dry it for a while before applying glue.

4) Tap the closed-cell rubber sponge board, especially the four corners of the air duct, with a rubber hammer to make it adhere to the air duct.

5), check the insulation appearance, if there is any inappropriate repair in time.

4. glass wool board insulation technology of aluminum foil.

1), first wipe the surface of the air duct clean, wipe off the dust and water on the surface, and dry it;

2) Bonding insulation nails. The length of insulation nail should be greater than the thickness of insulation cotton. The bonding density of the side and bottom of the air duct is 12 pieces/㎡, and the top is 9 pieces/㎡. Nail to nail spacing is not more than 450㎜, not more than 75 ㎜ from the edge of the duct;

3), cutting aluminum foil glass wool board, using a hacksaw to cut the plate, to make the long side of the thermal insulation material clamp short side, small pieces of thermal insulation material should be used as far as possible in the upper horizontal plane of the air duct;

4) Pave aluminum foil glass wool board, gently stick the cut aluminum foil glass wool board on the air duct, use a little force to make the insulation nail pass through glass wool board, and fix it with insulation nail gland after checking it. The gland should be moderately elastic and evenly compressed;

5), paste aluminum foil tape. Glass wool board flat-fell seam should be sealed by aluminum foil tape. Tape flat-fell seam width of 50㎜, duct angle of 80㎜. When sticking the tape, the force should be even and moderate;

6), glass fiber cloth, glass fiber cloth width should be 300 ~ 500 ㎜, winding should make them overlap each other by half, so that the appearance of thermal insulation materials forms two layers of glass fiber cloth winding;

7), brush fire retardant coating. Finally, brush the fire retardant paint on the glass cloth twice. When brushing, brush along the winding direction of glass fiber cloth, and brush tightly and evenly, and take necessary protective measures to avoid polluting other parts.

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