Foam/Rim Seal Protection is a method used in fire protection systems to prevent the spread of fire in storage tanks containing flammable liquids, such as crude oil, gasoline, or ethanol. The foam seal forms a barrier between the flammable liquid and the air, preventing the formation of flammable vapor-air mixtures.
Here's how it typically works:
Foam is generated either externally and then injected into the rim seal or generated directly within the rim seal area. This foam is usually a low-expansion type, designed to spread out and cover the entire rim seal area efficiently.
The foam is applied to the rim seal of the storage tank, which is the junction between the floating roof and the tank shell. This area is particularly vulnerable to the spread of fire because it is exposed to both the liquid contents of the tank and the external atmosphere.
Once applied, the foam forms a seal over the rim, creating a barrier that prevents the escape of flammable vapors and limits the ingress of oxygen, thus reducing the risk of ignition.
In the event of a fire, the foam acts as a fire suppressant by cooling the fuel surface and smothering the flames. It also helps to prevent the re-ignition of the flammable vapors.
