Oil-soaked insulation

Oil spillages onto warm, absorbent materials, such as insulation, also have a limited life (see Sections 7.3.2 and 12.4.4). The oil soon decomposes to materials with a low auto-ignition temperature and self-ignites. As many insulation fires have started in this way, oil-soaked insulation should be removed without delay. Linseed oil ignites particularly easily. This has been known since at least 1925 nevertheless, in 1965 some cloths used to apply linseed oil to laboratory benches were not burned as directed but dropped into a waste bin. A fire started after a few hours and destroyed the laboratory [17J. Reference 18 lists substances that are liable to self-heat, and Reference 19 includes references to a number of incidents that have occuiTed involving substances as diverse as wood shavings, tobacco, milk powder, and soap powder. 

Oil-soaked insulation can auto-ignite. The insulation holds the oil vapors near the heat source and prevents the oil trapped in the insulation from cooling. Furthermore, the heavy oils trapped in the insulation on very hot lines may be cracked to release lighter materials in the kerosene and diesel range, which are easier to ignite. When fed by dripping heavy oil, the oil-soaked insulation can smolder for extended periods. 

Thermal insulation (or lagging) on plant equipment may become soaked or impregnated witli oils and otlier flanuiuible liquids. When the lagging gets hot, spontaneous combustion can occur. Lagging fires are affected by oil laiks, insulation material, and temperature. Spontaneous combustion occurs only when tlie oil is nonvolatile, since volatile oil evaporates more easily, tlius delaying tlie... 

Pipe insulation should be noncombustible. Where hot piping insulation can be exposed to hydrocarbon leaks it should be provided with metal weather jacketing because oil soaked into the insulation can autoignite at line temperatures as low... 

The assembly is then wrapped with a few additional layers of tissue paper, the paper is lightly soaked with oil, and the assembly is finally wound with Pt wire. The wound assembly is coated with a water-dispersed ceramic powder and allowed to dry. It is recoated after drying and inserted into a suitable porcelain tube while still moist. Any free ace is filled with insulating cotrpound. After air drying, it should be dried thoroughly in an... 

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