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