Hot surfaces break the normal rules of coating selection. A binder that performs well at ambient temperature may soften, chalk or simply decompose at elevated service temperature, and thermal cycling adds stress that a standard atmospheric system was never designed for. The selection starts from the maximum continuous surface temperature, not from the corrosivity category.
Power plant flue gas ducts and hot surfaces
Heat-resistant and acid-resistant systems for stacks, ducts and equipment operating above ambient temperature.
Power plant flue gas ducts and hot surfaces — Heat-resistant and acid-resistant systems for stacks, ducts and equipment operating above ambient temperature. Service environment: C5-I plus elevated temperature; typical design life: 10–20 years. The table below lists the recommended coating build-up and links to the matching product categories and selectable products.
Recommended coating system
| Layer | Type & DFT | Product examples |
|---|---|---|
| Below ~120 °C | Zinc-rich epoxy primer + MIO epoxy + PU topcoat | Standard heavy-duty build |
| 120–200 °C | Zinc silicate or heat-resistant epoxy, no PU topcoat | Heat-resistant system |
| 200–400 °C | Silicone-based or specialised heat-resistant coating | Heat-resistant coating |
| Acid condensate zones | Glass-flake or novolac epoxy where temperature allows | Glass-flake / novolac |
Application critical points
- Establish the maximum continuous surface temperature and any thermal cycling first — it decides the binder family, and no topcoat choice can compensate for the wrong one.
- In flue gas systems, acid condensation at the cold end drives the corrosion. The dew point of the gas, not the average temperature, sets the requirement there.
- Above the service temperature limit of polyurethane, a heat-resistant finish must replace it; a PU topcoat will discolor and degrade even if the primer survives.
Related product categories
Related products from the brands used in this scenario
Related brands & products
Frequently asked questions
Which coating system is recommended for Power plant flue gas ducts and hot surfaces?
The recommended build-up is: Below ~120 °C; 120–200 °C; 200–400 °C; Acid condensate zones.
What is the service environment for Power plant flue gas ducts and hot surfaces?
Service environment: C5-I plus elevated temperature; typical design life: 10–20 years.
Which brands are covered by this scenario?
Brands covered by this scenario: AkzoNobel International, JOTUN, CMP, ZINDN.
Articles are compiled by RichTech from publicly available manufacturer materials and field practice, for selection reference only; the latest official technical data sheets (TDS) prevail.
Not sure which product fits? Tell us the substrate and service conditions
Share your substrate, corrosivity category and target service life — we will come back with a coating system and quantity estimate.