ProSolvr logo

Resolve problems, permanently

Root Cause Analysis for Boiler Tube Leaks

RCA of Boiler Tube Leaks

Boiler tube leaks in thermal power plants occur when the tubes that carry water or steam inside the boiler develop cracks, ruptures, or corrosion-induced holes. These leaks are a serious issue because they disrupt the heat transfer process, lower boiler efficiency, and can force an unexpected plant shutdown. In severe cases, boiler tube leaks can lead to safety hazards, costly repairs, prolonged downtime, and reduced power generation capacity, directly impacting both operational reliability and economic performance.

A fishbone template can be invaluable for conducting root cause analysis of various issues in a thermal power plant, like boiler tube leaks. By breaking down the problem into various contributing factors, the Gen-AI powered RCA enables maintenance teams to focus on all possible angles, ensuring that no potential cause is overlooked. It facilitates a structured brainstorming process, where team members can collectively analyze and list possible reasons for the leaks, such as material defects, operational errors, maintenance issues, environmental factors, and design flaws.

In a thermal power plant, multiple departments such as operations, maintenance, engineering, and quality control need to work together to resolve complex issues like boiler tube leaks. A Gen-AI powered root cause analysis application like ProSolvr encourages cross-functional collaboration and fosters a culture of continuous improvement. By mapping out the various causes and their associated sub-causes, the Ishikawa diagram provides a clear and comprehensive view of all potential factors, making it easier to pinpoint the root causes of the boiler leaks.

ProSolvr's systematic approach helps thermal power plants in prioritizing the most critical issues that need immediate attention and formulating effective corrective actions.

Boiler Tube Leaks

    • Material
      • Material Degradation
        • Erosion
        • Corrosion
      • Quality of Material
        • Incorrect Composition
        • Impurities
    • Design
      • Material Selection
        • Incorrect Tube Thickness
        • Inappropriate Material for Operating Conditions
      • Tube Layout
        • Insufficient Tube Spacing
        • Poor Circulation Design
    • Operation
      • Operational Practices
        • Poor Water Chemistry Control
        • Rapid Load Changes
      • Operating Conditions
        • Thermal Fatigue
        • Overheating
    • Maintenance
      • Repair Quality
        • Use of Substandard Replacement Parts
        • Poor Welding Practices
      • Inspection Frequency
        • Inadequate Inspection Techniques
        • Infrequent Inspections
    • Environment
      • Atmospheric Conditions
        • Industrial Pollution
        • High Humidity
      • Water Quality
        • Presence of Contaminants
        • High Dissolved Solids

Suggested Actions Checklist

Here are some corrective actions, preventive actions and investigative actions that organizations may choose from:

    • Material
      • Material Degradation
        • Corrective Actions:
          • Replace degraded tubes with certified replacement tubes and perform immediate integrity testing (hydrostatic/pressure test) before returning to service.
        • Preventive Actions:
          • Implement a scheduled material health monitoring and life-cycle replacement program based on metallurgical aging criteria.
        • Investigative Actions:
          • Conduct a metallurgical failure analysis (microstructure, hardness, fracture surface) to determine degradation mechanisms and service life remaining.
      • Quality of Material
        • Corrective Actions:
          • Quarantine and replace tubing supplied from suspect batches; reject further use of non-conforming material.
        • Preventive Actions:
          • Strengthen incoming material inspection and supplier quality agreements including certificates of conformity, mill test reports, and sample testing.
        • Investigative Actions:
          • Trace and audit supplier lots and review material certificates; perform chemical and mechanical verification tests on retained samples.
    • Design
      • Material Selection
        • Corrective Actions:
          • Replace inappropriate tubes with material specified for the service environment (temperature, chemistry, erosion/corrosion resistance).
        • Preventive Actions:
          • Update design standards and procurement specs to mandate materials matched to operating conditions and service life targets.
        • Investigative Actions:
          • Review design basis and selection criteria; run a material suitability assessment comparing expected service conditions against material properties.
      • Tube Layout
        • Corrective Actions:
          • Modify or retrofit tube bundle layout in affected zones (add spacers/shields or reconfigure) to alleviate identified stressors and circulation issues.
        • Preventive Actions:
          • Include CFD/thermal-hydraulic validation in design stage and maintain validated layout templates for similar units.
        • Investigative Actions:
          • Conduct a layout impact assessment (thermal-hydraulic modeling and inspection data) to determine how layout contributed to the leak locations.
    • Operation
      • Operational Practices
        • Corrective Actions:
          • Temporarily change operating procedures (reduce ramp rates, lower maximum allowed load) and retrain operators on safe operating windows.
        • Preventive Actions:
          • Standardize and document operating procedures with mandatory competency training and periodic re-certification for operators.
        • Investigative Actions:
          • Review operator logs, shift handovers, and procedure adherence records to find deviations that correlate with failure events.
      • Operating Conditions
        • Corrective Actions:
          • Adjust plant operating envelope (reduce overheating cycles, implement controlled ramping) and stabilize conditions to prevent further damage.
        • Preventive Actions:
          • Define and enforce limits for thermal cycling and overload events; implement operational safeguards (interlocks, alarms).
        • Investigative Actions:
          • Analyze recent operating history and event logs to correlate excursions (temperature, pressure transients) with tube failure incidents.
    • Maintenance
      • Repair Quality
        • Corrective Actions:
          • Rework or redo defective repairs using qualified personnel and approved procedures; inspect and test repaired areas before service.
        • Preventive Actions:
          • Establish repair quality standards, certified repair contractors, and mandatory weld/repair procedure qualifications.
        • Investigative Actions:
          • Audit past repair records, workmanship, and adherence to repair procedures to identify recurring poor repair practices.
      • Inspection Frequency
        • Corrective Actions:
          • Immediately increase inspection cadence in high-risk areas and perform comprehensive inspections (borescope, ultrasonic) to detect other compromised tubes.
        • Preventive Actions:
          • Implement a risk-based inspection schedule that sets minimum frequencies based on operating history, criticality, and degradation rates.
        • Investigative Actions:
          • Review historical inspection intervals and findings to determine whether infrequent inspections allowed degradation to progress undetected.
    • Environment
      • Atmospheric Conditions
        • Corrective Actions:
          • Mitigate local atmospheric exposure (install enclosures, filters, or sacrificial barriers) and clean affected surfaces to stop further external corrosion.
        • Preventive Actions:
          • Implement environmental controls (ventilation, filtration) and include atmospheric exposure assessments in siting/maintenance planning.
        • Investigative Actions:
          • Survey local environmental conditions (pollutant monitoring, humidity records) and correlate with corrosion/pitting patterns on tubes.
      • Water Quality
        • Corrective Actions:
          • Treat feedwater immediately (filtration, softening, chemical dosing) and flush systems to remove contaminants and high dissolved solids.
        • Preventive Actions:
          • Install or upgrade water treatment and monitoring systems with set action limits for contaminants and dissolved solids.
        • Investigative Actions:
          • Sample and analyze water chemistry (TDS, hardness, chlorides, suspended solids) and trace contaminant sources upstream in the water circuit.
 

Who can learn from the Boiler Tube Leaks template?

  • Operations and Maintenance Teams: These teams are directly responsible for the daily functioning and upkeep of the plant. This knowledge helps in enhancing the efficiency and reliability of the plant operations, reducing downtime, and extending the lifespan of the equipment.
  • Engineering Teams: Engineers can benefit from RCA by gaining insights into design flaws or material weaknesses that contribute to boiler leaks. This information is crucial for making design improvements, selecting more suitable materials, and incorporating better safety and reliability features into future projects.
  • Design Teams: Learning from past issues enables design teams to create more robust and leak-resistant boiler systems, thereby improving overall plant performance and safety.
  • Management Personnel: Senior management can use the findings from the RCA to make informed strategic decisions. Understanding the root causes of boiler leaks allows them to allocate resources more effectively, prioritize maintenance and upgrade projects, and develop comprehensive risk management strategies.
  • Policy Makers: This knowledge also helps decision-makers in creating policies and procedures that promote a culture of continuous improvement and proactive problem-solving, ultimately leading to enhanced operational efficiency and reduced costs.

Why use this template?

The visual nature of the RCA template helps in presenting the problem and its causes in a way that is easily understandable by all stakeholders, facilitating better communication and coordination. Quality tools like ProSolvr from smartQED aid in reducing downtime, improving the reliability of the boiler system, and enhancing the overall efficiency of the thermal power plant. By involving different perspectives, the analysis becomes more thorough and well-rounded, leading to more robust solutions.

Use ProSolvr by smartQED for understanding the root causes of various issues to improve your maintenance practices, adopt better operational procedures, and implement preventive measures to avoid future risks.

Curated from community experience and public sources:

  • https://www.getchemready.com/water-facts/top-5-reasons-why-boiler-tubes-leak/
  • https://www.babcock.com/home/about/resources/learning-center/finding-the-root-cause-of-boiler-tube-failure