Foam Chambers

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The CHEMGUARD® foam chambers consist of a foam expansion chamber and an integral foam maker with a stainless steel screened air inlet. Each chamber includes an orifice plate, two inlet gaskets, vapor seal assembly, cover gasket, and an outlet gasket. The required deflector (split or shallow) and optional mounting pad assembly are sold separately.

A removable orifice plate located at the flanged inlet to the foam maker is sized to deliver the required flow rate of foam solution at a specified inlet pressure. A frangible TEFLON vapor seal is burst upon entry of foam solution allowing an unrestricted flow of expanded foam into the chamber body. From the chamber body, the foam flows through the foam deflector which disperses the foam into the storage tank.

The chamber vapor seal is accessible for inspection and service through a hinged inspection hatch that is secured with captive bolts. The hatch also contains a lifting handle that is designed to support the weight of the foam chamber.

The foam deflector directs the foam stream down the tank sidewall to lessen the submergence of the foam and agitation of the fuel surface (Type II application). The foam deflector is a split (two-piece) style. The split deflector allows for either bolting or welding to storage tanks when installation may be performed from both sides of the tank wall as with newly constructed tanks. The split deflector also allows for insertion of the deflector through the flange opening from the outside wall as is often required with tanks already in service.

The foam chamber and deflector can be bolted to the storage tank using a mounting pad. The pad contains mounting studs to fit standard flange holes.


  • Choice of four foam chamber sizes for various foam solution flow rate requirements
  • Hinged inspection hatch with captive bolt securement for ease of inspection and maintenance
  • Choice of carbon steel or 304 stainless steel with corrosion resistant (CR) epoxy paint finish
  • TEFLON* vapor seal allows unrestricted flow of expanded foam
  • Convenient vapor seal replacement without removal of retaining bolts
  • UL Listed


CHEMGUARD® foam chambers are air-aspirating foam discharge devices that are used to protect various types of flammable liquid storage tanks including open top floating roof tanks and cone roof tanks with or without internal floaters. Additional applications include most types of open tanks where flammable liquid products are involved.

Foam chambers are defined by NFPA 11 as Type II discharge outlets for delivering foam to the surface of a flammable liquid. They are commonly used with bladder tanks, balanced pressure pump proportioning systems, line proportioners, or foam trucks. These foam chambers can be used with CHEMGUARD® lowexpansion foam agents that are determined to be suitable for the flammable liquid being protected.