Overhead foam injection

Overhead foam injection systems are provided for the protection of atmospheric or low pressure storage tanks. They consist of one or more foam chambers installed on the shell of a tank just below the roof joint. A foam solution pipe is extended from the proportioning source, which is located in a safe location, to a foam aspirating mechanism just upstream of the foam chamber or pourer. A deflector is usually positioned on the inside tank wall at the foam chamber. It is used to deflect the foam against the tank wall and onto the surface of the tank or the tank and the shell seal area. 

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