Map the high-temperature zones first (power plant isn’t one temperature)
Most coating failures in power plants start with one mistake: using a single coating idea across areas that behave very differently in service.
Typical high-temperature zones
- Boiler area and nearby steelwork (radiant heat + thermal cycling).
- Steam pipelines and hot equipment (often insulated; CUI risk is common on hot/insulated networks).
- Exhaust and flue systems (high heat + acidic condensate risk during start/stop in some designs).
Decision rule (fast): if a line is insulated, treat it as “corrosion-risk + temperature” even if the outside surface doesn’t feel extremely hot during operation.
Zone-to-system table (use for RFQ alignment)
| Zone / component | Dominant damage drivers | Coating system direction | What to define in the spec |
|---|---|---|---|
| Boiler-side steel & hot equipment | Thermal cycling, heat aging, corrosion at details | Heat-capable system + detail strategy | Max operating temp range; shutdown cycles; edges/weld plan |
| Steam pipelines (often insulated) | CUI, wet/dry under insulation, handling damage | CUI-aware primer + heat-capable topcoat | Insulation type; sealing strategy; repair rules |
| Exhaust/flue/stack externals | High heat + weathering | High-heat silicone family topcoat | Surface temp band; color/appearance needs |
Why standard anti-corrosion coatings fail at high temperatures
“Good corrosion paint” can still fail when the binder chemistry is pushed beyond its heat limits or when thermal cycling is ignored.
Common failure mechanisms
- Thermal aging: binder degrades and loses flexibility, which increases cracking risk.
- Adhesion drop: cycles and heat can weaken intercoat bonding when recoat windows or surface conditioning are not controlled.
- Embrittlement: film becomes harder and less tolerant to vibration and movement.
A practical benchmark from industrial high-temperature coatings guidance is that typical epoxies have lower heat resistance than silicone systems, and high-heat silicone coatings are commonly used on hot exterior steel such as stacks and boilers across broad high-temperature ranges.
Types of high-temperature coatings used in power plants
Selection should follow service temperature band, corrosion mechanism, and whether insulation is present.
Silicone-based coatings (high-heat topcoats)
These are widely used for higher surface temperatures, especially on stacks/boilers and other hot exterior steel, because silicone systems tolerate higher heat than many conventional binders.
Aluminum-pigmented heat-resistant systems
Aluminum pigmentation is often used to improve heat reflectivity and stability in high-temperature service and can be a practical choice for hot steel where appearance is less critical than durability.
Inorganic coatings (often inorganic zinc primers)
Industrial guidance notes that inorganic zinc is commonly used in high-temperature new construction, sometimes topcoated with thin-film high-heat silicone systems for combined corrosion control and heat resistance.
If you need a starting point for power-plant scope and typical protection targets, use HUILI’s application page as a baseline reference: Power Plant Industrial Coatings.
Design the system the “power plant way”
Step 1: Define the temperature bands and cycles
Ask for operating temperature range, start/stop frequency, and whether the steel will see repeated thermal shock (this affects cracking/adhesion risk more than peak temperature alone).
Step 2: Decide the corrosion problem (not just heat)
- Insulated hot lines: prioritize CUI-resistant design and repairability; CUI is frequently highlighted as a concern in industrial facilities with extensive hot/insulated networks.
- Outdoor hot steel: prioritize weathering plus heat.
- Internal exhaust/flue areas: consider condensate/chemistry and shutdown conditions.
Step 3: Specify surface preparation as a measurable deliverable
Use recognized preparation standards (ISO 8501 and SSPC/NACE equivalence) and define hold points and acceptance checks; a practical overview of these standards and how they’re referenced in specifications is summarized by Graco.
Step 4: Control film build and application windows
Specify DFT as ranges by layer (primer and topcoat), and require recoat interval logging; this prevents intercoat delamination and under-cure problems that show up after commissioning.
Step 5: Pre-define repairs and touch-up
Power plants will have handling damage and maintenance work; require a repair procedure and re-inspection steps so the site doesn’t “invent” fixes under schedule pressure.
If your RFQ includes silicone high-temperature anti-corrosion coating around 250–300°C class service, HUILI lists a two-component silicone system for that band (use it for TDS alignment and scope definition): 250/300 Silicone High-Temperature Anti-Corrosion Paint.
Where failures start (and what to inspect)
Common failures + troubleshooting
- Early peeling on hot steel: often tied to surface prep shortfalls, contamination, or missed recoat windows.
- Cracking on hot/cycling areas: usually a temperature/cycle mismatch or brittle film build.
- CUI-driven corrosion: commonly caused by water ingress at insulation joints, poor sealing, and unplanned repairs.
Quality / inspection checklist (DFT, recoat, surface prep)
- Surface prep hold point: verify prep grade and cleanliness before priming, using ISO/SSPC/NACE language in the ITP.
- DFT checks: record primer/topcoat DFT as ranges per TDS, with extra readings at welds, edges, clamps, and supports.
- Recoat control: log recoat time windows and surface condition (especially after rain, wash-down, or night cooling).
- Insulation interfaces (if any): confirm sealing steps, repair access rules, and inspection frequency for high-risk wet points.
- Handover dossier: include batch traceability, DFT logs, repair logs, and as-built zone map.
RFQ checklist
- Equipment list and zones (boiler area, steam lines, flue/stack; insulated vs bare).
- Surface temperature ranges by zone and expected thermal cycles/start-stop frequency.
- External exposure: coastal/industrial/UV, plus wash-down or chemical splash areas.
- Substrate and condition: new build vs maintenance; existing coating type (if any).
- Surface preparation method available and constraints (blast vs power tool).
- Required deliverables: TDS/SDS, system recommendation sheet, application method statement, QC checklist, repair procedure.
Technical Note
Final coating system selection, DFT ranges, surface preparation level, and acceptance criteria must be confirmed by the applicable TDS and project specification.
CTA
Contact us to select high temperature coating systems suitable for your power plant project—share your temperature zones, insulation/CUI risk areas, and surface preparation constraints via Contact.
