Balance Type Foam Proportioning Device Balance type foam proportioning device is a new type foam proportioning device for supplying foam mixed liquid to foam fire protection system. It has advantage of more foam liquid storage, good reliability and continuously supply to meet the requirements of large-scale foam fire protection engineering. Besides, it stores foam liquid in concentrate tank with normal pressure and no bladder, so it can avoid bladder damaging to reduce the maintenance charges and manufacturing cost. It is mostly used in serious fire situation, such as large-scale petrochemical industry, tank farm, petrochemical dock, airport, offshore platform etc. Advantages of the device: 1. Balance valve can adjust the quantity of foam liquid entering into foam proportioner to insure accurate mixed proportion. 2. Because foam liquid is supplied by foam pump, the range of operation pressure and flow rate of mixed liquid are wide. 3. The concentrate tank is made of stainless steel (glass reinforced plastics or polyethylene ) with normal pressure and no bladder, so it can avoid bladder damaging and reduce the manufacturing cost. 4. The inhalation valve can balance the pressure inside and outside the concentrate tank. 5. Pressure relief/keep valve can insure the safe of operation pressure in pipeline. 6. All the present foam extinguishing agent (protein foam, fluoroprotein foam, aqueous film-forming foam and so on.) can be used in this device. 7. It can be added foam concentrate during extinguishing at any time to meet the requirements of large-scale fire protection engineering. 8. The device can be controlled by automatically and manually.