A foam bladder tank is a steel pressure vessel containing an elastomeric bladder that separates water and firefighting suspension (foam concentrate).
When the fire system is activated, pressurized water fills the space between the tank wall and the membrane, compresses the bladder, and displaces the foam concentrate to the proportioner. The proportioner mixes the concentrate with water in the required ratio, thus forming foam for extinguishing.
This system does not require a separate pump for the foaming agent — it operates on water pressure, which simplifies the design and increases reliability.
Advantages of Foam Bladder Tank
- Stable foam concentrate dosing — even with variable pressure or water flow, the concentrate/water ratio remains constant.
- No need for electricity or a separate foam concentrate pump — everything works under water pressure.
- Minimal maintenance and durability — the design is durable, and maintenance is limited to checking the condition of the membrane, tightness, etc.
- Flexibility in installation — tanks can be vertical or horizontal, depending on space, design, or installation conditions.
- Compatibility with various foam concentrates — different types of concentrates can be used (depending on compatibility), providing flexibility in designing fire suppression systems for various conditions.
Main technical characteristics (for vertical and horizontal versions)
- Housing and bottoms — high-strength steel (e.g., ASTM A516 Gr.70 or EN-certified materials).
- Membrane (bladder) — made of elastomers (e.g., Hypalon-neoprene, NBR/EPDM) with sufficient resistance to compression, chemical exposure to concentrates, and temperatures.
- Working pressure — standard ~ 12 bar (175 psi), tested at ~ 16 bar (or more, depending on model and certification).
- Components: tank body, bladder, trim valves for water and concentrate supply/drainage, ratio controller, shut-off valves, drain/ventilation, sight gauge/level indicator.
- Installation type:
- Vertical tank — installed on legs or supports; takes up a minimum of floor space.
- Horizontal tank — installed on saddles; more convenient for installation, maintenance, filling, often the choice when height is limited or the layout is specific.
- The standard color is fiery red (e.g., RAL 3000 or similar), with an anti-corrosion coating (epoxy primer + polyurethane finish).
Areas of application for Foam Bladder Tanks:
Foam Bladder Tanks are widely used in fire extinguishing systems for facilities with an increased risk of fire, especially where Class B fires (flammable liquids, oil, chemicals) are possible, as well as for complex sprinkler, deluge, foam monitor, and other systems.
Typical facilities:
- oil depots, fuel terminals, tank farms
- chemical plants, oil refineries, storage sites with flammable liquids
- airports, hangars with aviation fuel
- marine and offshore platforms, oil and gas processing enterprises
