Introduction
Butterfly valves are known for reliability, but proper maintenance is essential for maximizing service life. This guide covers maintenance best practices for both double eccentric and triple eccentric designs.
Preventive Maintenance Schedule
Monthly Inspections
- Visual check for external leakage
- Verify valve position indicator accuracy
- Check actuator air supply (pneumatic)
- Inspect electrical connections (electric)
Quarterly Maintenance
- Exercise valve through full stroke
- Check stem packing for leakage
- Inspect gear operator lubrication level
- Clean external surfaces
Annual Service
- Complete operational test
- Replace stem packing if needed
- Grease worm gear operator
- Inspect flange gaskets
- Document valve condition
Lubrication Guidelines
Worm Gear Operators
| Component | Lubricant Type | Interval |
|---|---|---|
| Worm gear | Lithium-based NLGI 2 | 12 months |
| Bearings | Same as gear | 12 months |
| Stem | Anti-seize compound | During packing service |
Actuators
Follow manufacturer guidelines for pneumatic and electric actuators. Generally:
- Pneumatic: Check lubricator levels monthly
- Electric: Grease motor bearings annually
Troubleshooting Common Issues
High Operating Torque
- Check for media buildup on disc
- Verify packing is not over-tightened
- Inspect for stem corrosion
- Check actuator air pressure
External Leakage
- Stem packing: Adjust or replace
- Body joints: Check gasket condition
- Flange connections: Verify bolt torque
Internal Leakage
- Soft-seated: May require seat replacement
- Metal-seated: Check for damage to sealing surfaces
- Verify proper torque/positioner calibration
Storage Recommendations
For spare valves or seasonal shutdown:
- Store in closed position
- Protect seating surfaces
- Indoor storage preferred
- Exercise every 6 months minimum
XHVAL Support
XHVAL provides comprehensive maintenance support:
- Spare parts availability: 20+ years
- Technical documentation
- Field service support
- Training programs
Conclusion
Regular maintenance significantly extends valve service life and prevents costly unplanned shutdowns. Implementing a preventive maintenance program ensures reliable operation and protects your investment.