When choosing a suitable pipe repair airbag, you need to consider multiple factors such as the size, material, and repair methods of the pipe. The following are the specific points:
1. Pipe size
1. Accurate measurement: Accurate measurement of the inner diameter of the pipe is the key to choosing an airbag. Different pipe repair airbags have their specific applicable pipe diameter range. For example, common airbag specifications may be suitable for pipes of DN100 - DN1000mm. The airbag that can match it should be selected according to the actual pipe size to ensure that the airbag can fit closely with the inner wall of the pipe after inflation and provide uniform pressure.
2. Consider tolerances: A certain tolerance range should be considered when measuring, because the actual inner diameter of the pipe may change due to factors such as manufacturing errors, wear or deformation. Generally speaking, the diameter of the airbag should be 10%-20% larger than the inner diameter of the pipe to ensure good sealing and fitting effect.
2. Pipe material
1. Characteristics of different materials: The surface characteristics and physical properties of pipes of different materials are different, so you need to choose an airbag that is suitable for it. For example, the surface of metal pipes is smooth but hard, and the airbag needs to have sufficient wear resistance and strength to withstand pressure; while the surface of plastic pipes is relatively soft, the material of the airbag should avoid damage to the pipes, and it should be able to adapt to the thermal expansion and contraction characteristics of plastic pipes.
2. Chemical compatibility: If the pipe is transported with corrosive media, or the materials used during the repair process may react chemically with the pipe material, then choose an airbag with corresponding chemical resistance to prevent the airbag from being corroded or damaged.
3. Repair method
1. Lining repair: If the lining repair method is used, you need to choose an airbag that can provide uniform pressure and ensure that the lining material is closely fitted with the inner wall of the pipe. Such airbags usually require high flexibility and strength to accommodate pipes of different shapes and long-term pressure requirements. For example, when repairing with fiber reinforced composite lining, the pressure of the airbag is to allow the lining material to be fully impregnated with the resin and seamlessly bond with the inner wall of the pipe.
2. Local repair: For local repairs, such as repairing cracks or holes in the pipeline, you can choose airbags with smaller sizes that can be accurately positioned in the damaged area. Such airbags need to have good positioning and stability in order to remain in a specific position during the repair process, providing support and pressure for the repair material.
4. Work pressure
1. Determine according to the repair requirements: Different repair processes and materials have different requirements for the working pressure of the airbag. For example, some heat-curing lined repair materials require higher pressures to ensure the curing effect of the material, usually operating pressures between 0.2 and 0.5MPa; while for some simple seal repairs, lower pressures (such as 0.1 and 0.2MPa) may be sufficient. The required airbag operating pressure should be determined based on the specific repair materials and process instructions.
2. Pressure tolerance of airbag: The selected airbag must be able to withstand the required working pressure and must have a certain safety margin. Generally speaking, the rated operating pressure of the airbag should be 20% - 30% higher than the actual pressure required to prevent the airbag from rupturing or damage due to excessive pressure.