1. Pipelines with Large Deformation/Displacement and Limited Spatial Position

• In pipelines where spatial constraints (e.g., narrow installation spaces, complex routing) restrict natural displacement, metal bellows efficiently absorb axial, lateral, or angular movements through their flexible corrugated structure. For example, in industrial workshops with compact layouts or urban pipeline networks crossing buildings, the joints adapt to limited space while compensating for thermal expansion or mechanical displacement.

2. Large-Diameter Pipelines with High Displacement and Low Working Pressure

• For pipelines with large diameters (e.g., DN300+), even low working pressures (e.g., ≤1.0 MPa) can generate significant thermal expansion or settlement displacement. Metal bellows expansion joints, with their high flexibility and large compensation capacity, are ideal for such scenarios—e.g., in municipal water supply/drainage networks, sewage treatment plant pipelines, or low-pressure gas transmission lines.

3. Equipment Requiring Restricted Nozzle Loads

• In sensitive equipment like boilers, heat exchangers, or reactors, excessive nozzle loads from pipeline displacement can cause structural damage. Metal bellows installed near equipment inlets/outlets isolate pipeline stress, reducing nozzle forces and moments to within allowable limits. This is critical in power plants, chemical plants, and refineries to protect expensive equipment.

4. Pipelines Requiring High-Frequency Mechanical Vibration Absorption/Isolation

• In systems with pumps, compressors, or turbines, high-frequency vibrations (e.g., 50-300 Hz) can lead to pipeline fatigue failure. The elastic corrugations of metal bellows dampen vibration transmission, converting mechanical energy into heat. 典型 applications include petrochemical pump discharge pipelines, HVAC chilled water systems, or industrial machinery connecting pipes.

5. Pipelines Needing to Absorb Seismic or Foundation Settlement Displacement

• In seismic zones or areas with unstable foundations, pipelines may experience abrupt lateral/vertical displacement during earthquakes or gradual settlement over time. Metal bellows expansion joints, with their multi-directional compensation capability, mitigate such displacement—e.g., in urban gas pipelines across fault zones or industrial pipelines in soft soil areas.

6. Absorbing Vibration at Pipeline Pump Exits

• Pump operation generates pulsating flow and mechanical vibration, which can cause pipeline resonance or joint leakage. Installing metal bellows at pump exits buffers these vibrations, protecting downstream pipelines and reducing noise. This is common in water supply stations, wastewater treatment pumps, and industrial fluid transport systems.
  
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Key Considerations for Proper Selection

• Pipeline dimensions: Nominal diameter (DN), wall thickness.
• Working pressure: Maximum operating pressure (e.g., 1.6 MPa, 2.5 MPa) to match the joint’s pressure rating.
• Medium and temperature: Properties of the conveyed medium (e.g., water, steam, acid, oil) and its temperature range (e.g., -20°C to 300°C), dictating material selection (stainless steel 304, 316L, Inconel, etc.).
• Connection method: Flanged, welded, or threaded connections, matching pipeline interfaces.
• Installation form: Axial, lateral, or universal types, depending on the displacement direction (e.g., axial expansion requires single-axial joints; complex movements need universal joints).
• Compensation amount: Calculated based on thermal expansion, settlement, or vibration displacement to ensure the joint’s stroke capacity (e.g., axial compensation ≥50 mm) matches operational needs.