In power plant insulation applications, rock wool boards outperform alternatives like polyurethane foam, glass wool, and extruded polystyrene (XPS) boards by better meeting the sector’s demands for high-temperature resistance, safety, and durability. Their core advantages fall into following key areas.

High-temperature Tolerance and Thermal Stability

Power plant boilers, steam pipelines, and similar equipment operate continuously in 300–600°C environments. Rock wool boards—withstanding 650°C for standard grades and up to 1000°C for high-temperature variants—remain intact without melting or deforming under heat. Their low linear expansion coefficient also lets them adapt to temperature fluctuations during boiler start-ups and shutdowns. By contrast, polyurethane and XPS only handle 80–120°C before softening and igniting, while glass wool (rated at ~280°C) shrinks and cracks above 300°C.

Safety

Classified as Grade A non-combustible materials, rock wool boards are made from inorganic minerals. They produce no open flames or toxic fumes when exposed to fire, effectively containing its spread. Polyurethane and XPS, mostly Grade B1/B2, release toxic smoke when burning, with molten drips that can trigger secondary blazes. Though glass wool is also non-combustible, its fibers become brittle and shed at high temperatures.

Corrosion resistance

Power plant flue gases and circulating water contain corrosive substances, but rock wool’s inorganic silicate composition ensures chemical stability. Its surface can be coated with anti-corrosion layers to boost impermeability. Polyurethane and XPS, however, degrade quickly when exposed to acids or alkalis, lasting just 5–8 years. Glass wool’s porous structure absorbs water easily, accelerating equipment rust.