【Fire-retardant coatings】What exactly is a hydrocarbon intumescent fire-retardant coating? ?

　 What exactly is a hydrocarbon intumescent fire retardant coating? Coatings are composed of various components (resins, fillers, fire-retardant additives, and other additives). After forming a film, hydrocarbon intumescent fireproof coatings are identical to ordinary paint films at room temperature. The fire resistance requirements for coatings dictate that they contain a large amount of fire-retardant additives, which facilitate the foaming and expansion of the coating. Corrosion resistance is required to effectively defend against the attack of external corrosive agents. Under the action of flame or high temperature, the coating undergoes intense foaming and carbonization, forming a flame-retardant foam carbonized layer that is dozens or even hundreds of times thicker than the original coating. It can prevent external heat sources from directly heating the substrate, thereby serving a flame-retardant function. 　　After the fireproof coating is foamed, its thickness increases by dozens of times, while its thermal conductivity decreases significantly. Therefore, the heat transferred to the substrate through the foamed carbonized layer is only a fraction of tens or even hundreds of that of the unexpanded coating, thereby effectively preventing the effect of external heat sources. On the other hand, under flame or high-temperature conditions, physical changes such as softening, melting, evaporation, and expansion of the coating, as well as chemical changes such as decomposition, degradation, and reaction of components like polymers and fillers, can absorb a large amount of heat energy. This helps to counteract some of the heat applied to the object from the outside, thereby delaying the heating process of the substrate that is being protected. 　　Furthermore, the non-flammable gases released by the coating upon decomposition at high temperatures can dilute the concentrations of flammable gases and oxygen produced by the thermal decomposition of organic materials, thereby suppressing the progression of combustion. Therefore, hydrocarbon intumescent fire retardant coatings are relatively effective flame-retardant coatings. It does not burn in low flames and goes out on its own when separated from the fire. It can prevent the spread of flames under intense fires and slow down the rate at which the fire spreads.

【Ten Years of Rapid Development in Chemical Processing Equipment】Gate valves of DN750 size for the largest domestic delayed coking units, 1065–2021 https://bbs.hcbbs.com/thread-4329872-1-1.html (Source: Haichuan Chemical Industry Forum Website)