Why repeated repairs do not create CFB boiler reliability

Repeated local weld repairs

In high-erosion CFB areas, repeated weld build-up can create uneven profiles and unpredictable wear. The immediate damage is repaired, but the underlying erosion pattern remains.

Generic thermal spray

A single material or thickness specification may not address the different erosion and corrosion mechanisms found throughout the boiler. Poor surface preparation, unsuitable materials or inconsistent application can also lead to premature failure.

Tube and panel replacement

Pressure-part replacement is costly, adds work to the outage critical path and may introduce tube-alignment issues that influence future wear.

A successful CFB strategy must address the boiler’s complete wear profile, not simply repair each defect after it appears.

Build a CFB reliability plan around actual wear

IGS combines inspection data, operating history, fuel characteristics and previous failure locations to develop a unit-specific SMARTGard® protection plan.

1. Assess and map

Review UT data, tube failures, existing protection and known high-wear areas.

2. Engineer the protection

Select the appropriate HVTS^® material, coverage and thickness for each degradation mechanism and target run length.

3. Apply during the outage

Protect priority areas using trained field teams and documented application procedures.

4. Measure and monitor

Track cladding condition and wear rates during planned inspections to confirm performance and support predictable future outage planning.

The result: A planned, scalable maintenance program that protects the substrate while making future outage scope more predictable.

Proven CFB boiler results

→ 500 tube repairs reduced to zero

After a previous thermal spray system resulted in 500 repairs in one year, IGS SMARTGard® reduced the requirement to five repairs in the first year and zero thereafter.

→ Quarterly interventions reduced to annual outages

A European supercritical CFB plant moved from quarterly interventions to planned annual outages, with zero tube leaks in protected areas since 2019 and boiler availability exceeding 90%.

→ Run cycles extended from 4–6 to 12–14 months

A coal-fired CFB plant more than tripled its operating cycle, eliminated forced outages during the reported period and reduced exposure to millions of dollars in annual maintenance and downtime costs.

→ From repeated welding to predictable maintenance

A two-unit CFB plant has used IGS protection since 2003, replacing repetitive weld repair with a measurable maintenance strategy and extending planned outage intervals to two years.

Explore more CFB case studies

“We moved from high, unpredictable labor hours to low, consistent, planned work—much better for outage planning and budgeting.”

– Joel Taylor, Boiler Engineering and Maintenance Specialist – CFB White paper 

Frequently asked questions

Can erosion be eliminated from a CFB boiler?

The circulation of abrasive particles is inherent to CFB operation, so erosion cannot be completely removed. It can, however, be managed with an engineered sacrificial protection layer that wears instead of the underlying pressure part.

How is IGS HVTS® different from conventional thermal spray?

The difference is not simply the spray equipment. IGS combines proprietary materials, controlled high-velocity application, surface preparation, quality documentation and a CFB-specific protection specification based on the boiler’s actual degradation mechanisms.

Does the entire cladding system need to be replaced at every outage?

Normally, no. The protection is inspected and measured during planned outages. Only areas approaching their minimum specified thickness need to be locally refurbished.

How long will the protection last?

Service life depends on the location, fuel, ash chemistry, operating conditions and measured wear rate. The specification is therefore designed around the plant’s required operating cycle rather than applying one standard thickness throughout the boiler.

What information is required for an evaluation?

Useful information includes recent UT or inspection data, boiler drawings, fuel characteristics, tube-failure history, existing weld or coating locations and the date and duration of the next planned outage.