Foam Chambers are suitable for the protection of fixed roof-mounted tanks and are to be used as low expansion Type II discharge devices (as defined by NFPA11) with approved and/or listed Foam Concentrates and Proportioning Devices. Foam Chambers are designed to apply an expanded foam blanket over the surface of a flammable liquid fire as gently as possible to achieve extinguishment and/or vapor suppression. A deflector positioned on the inside of the storage tank directs the expanded foam back onto the wall of the tank. The foam runs down the wall of the tank onto the liquid surface, minimizing submergence and fuel pick-up thereby maximizing the positive effect of the foam. Low Expansion Foam Deluge Systems are the preferred protection for large outdoor tanks of flammable liquids. Typical applications include manufacturing plants, large tank farms, oil refineries and chemical plants.