1. What are key elements of a tube failure prevention program?
Comprehensive water chemistry monitoring and control
Regular thickness measurements and NDT inspections
Operational parameter monitoring with alarm limits
Staff training on damage mechanisms and early warning signs
Root cause analysis of all failures with corrective actions
2. How does proper startup/shutdown protect tubes?
Controlled heating/cooling rates prevent thermal shock (typically 55-100°C/hour)
Minimum flow requirements ensure proper cooling before firing
Gradual pressure increase avoids cold stress
Automated startup sequences improve consistency
Special procedures for different boiler designs
3. What maintenance prevents fireside corrosion?
Regular sootblowing to remove corrosive deposits
Fuel quality monitoring and blending
Protective coatings on susceptible areas
Burner adjustments to minimize reducing atmospheres
Inspection of shield tubes and wear surfaces
4. How to prevent flow-accelerated corrosion?
Use chromium-containing alloys (1-3% Cr) in susceptible areas
Maintain proper pH (9.2-9.6) and reducing conditions
Avoid turbulent flow regimes in single-phase water
Regular UT thickness surveys of high-risk locations
Flow modeling to identify problem areas
5. What are best practices for outage inspections?
Pre-outage planning with risk-based focus areas
Combination of NDT methods for comprehensive assessment
Cleaning before inspection for accurate findings
Documentation with photos and measurements
Trend analysis comparing to previous inspections
