Aflex Metal Bellows Maintenance Procedures

Metal bellows assemblies are designed for long-term operation under specified conditions with minimal intervention. When installed and operated within design parameters, bellows are generally considered maintenance-free. However, periodic
inspections are recommended to ensure continued safe operation and to identify any signs of abnormal wear, damage, or environmental factors that may affect performance.

General Guidelines

  • Bellows assemblies require no routine maintenance under normal operating conditions.
  • Scheduled visual inspections should form part of the site’s general piping or plant maintenance routines.
  • Maintenance actions are typically limited to inspection and ensuring surroundingequipment does not impose unexpected loads or movements on the bellows.

Inspection Procedure

Recommended Frequency:
Visual inspection during routine shutdowns or at least annually, unless site conditions suggest otherwise.

Inspection Steps:
  1. Visual Examination:
    1. Inspect bellows convolutions for deformation, cracks, corrosion, or leaks.
  2. Attachment Points:
    1. Check welds, flanges, and tie rods for cracks, corrosion, or loose fasteners.
  3. Alignment and Supports:
    1. Verify pipe alignment remains within design tolerances. Confirm supports are intact.
  4. Movement Check:
    1. Ensure bellows are free to absorb designed movement and are not restricted.
  5. Protective Components:
    1. Inspect liners, covers, and insulation for damage or corrosion.

Corrective Actions

  • If leaks, cracks, severe deformation, or excessive corrosion are detected:
    • Isolate the system.
    • Replace the bellows assembly (bellows are generally non-repairable components).
  • If alignment or support issues are identified:
    • Rectify pipe misalignment or faulty supports before restarting the system.

Operational Considerations

  • Ensure system pressure, temperature, and movement stay within the bellows design limits.
  • Avoid excessive vibration, torsional loads (unless designed for torsion), or overextension beyond rated movement.

Record Keeping

  • Document inspection findings, including:
  • Date of inspection
  • Observations
  • Corrective actions (if any)
  • Retain inspection records as part of the plant maintenance log.

Important Notes

  • Bellows are not designed for field modification.
  • If damage or defects are suspected, consult the manufacturer before attempting repairs or replacements.
  • Replacement bellows should match the original design specifications to maintain system integrity.