Installation process and precautions of metal bellows pipes

Metal bellows pipes are specialized components used in various engineering applications. They are typically crafted from thin, flexible metal sheets, often stainless steel, that are corrugated to create an accordion-like structure. These pipes are designed to absorb axial, lateral, and angular movements, making them crucial for applications that require precise motion control while maintaining an airtight seal. Metal bellows pipes are commonly found in industries like , automotive, and industrial machinery, where their ability to handle conditions, including high temperatures, pressures, and corrosive environments, is vital. These durable and reliable components help prevent the overloading of pipes and equipment, ensuring the integrity and longevity of complex systems.

Metal bellows expansion joint: it is composed of one or more bellows and structural parts, and is used to absorb the size change of pipeline or equipment caused by thermal expansion.

1、 1- End plate; 2- Tighten the metal corrugated pipe; 3- Pull rod or positioning screw; 4- Nut; 5- Inner liner; The expansion joint must be strictly accepted before installation, and the product certificate and operation instructions are complete.

2. The expansion joint must be equipped with transportation parts to ensure the length of the compensation joint is fixed during transportation and installation. After the compensation joint is installed, the transportation parts must be removed or loosened before the system pressure test.

3. The model and specification of the expansion joint shall be checked before installation, and the pipe support configuration must meet the design requirements. During the installation process, welding slag should not splash onto the surface of the corrugated pipe and cause other mechanical damage to the corrugated pipe. For the expansion joint with an inner gasket, pay attention to ensuring that the direction of the inner gasket corresponds to the flow direction of the medium (installed according to the flow direction sign of the expansion joint). The rotation plane of the angle expansion hinge joint in the plane must correspond to the displacement plane. For the expansion joint to be cold-tightened, the auxiliary components used for deformation must be removed after the installation of the pipeline system.

4. All moving elements of the expansion joint shall not be stuck by external elements or restrict the normal movement of its moving parts. After the installation of the pipeline system, the additional positioning mechanism on the expansion joint and the fasteners for installation and transportation protection shall be removed immediately, and the limit device shall be adjusted to the specified position according to the design requirements so that the pipeline system can fully compensate for the environmental conditions.

5. Spot welding and false welding are not allowed when welding pipeline supports or brackets. The installation of an expansion joint must ensure the coaxiality. First, lay the pipe section, then cut a section of pipe with the same length as the expansion joint at the place where the expansion joint is to be installed, and then install and weld the expansion joint. It is not allowed to forcibly adapt to the deviation of pipeline installation through the deformation of the compensator.

6. The expansion joint used for the gas medium and its connecting pipe must be temporarily supported during the hydraulic test to prevent the expansion joint and pipe from slipping off. After the pressure test, remove the temporary support. If the unrestricted expansion joint pipe is selected for the sectional pressure test, the intermediate fixed support must be reinforced to withstand the initial design load and the thrust of the internal pressure shield.