泡沫比例混合装置是泡沫灭火系统的核心部件 ,其可靠与否、性能优劣 ,关系到整个系统是否可靠 ,所以选择何种泡沫比例混合装置应充分比较、论证。目前固定泡沫灭火系统通常所用的泡沫比例混合装置有环泵式泡沫比例混合装置 ,压力式泡沫比例混合装置、平衡压力式泡沫比例混合装 Foam proportioning device is the core component of foam fire extinguishing system. Whether its reliability or not, performance is good or not depends on whether the whole system is reliable or not. Therefore, it is necessary to fully compare and demonstrate which kind of foam ratio mixing device should be chosen. At present, the foam ratio mixing device commonly used in the fixed foam fire extinguishing system includes a ring-pump foam proportioning device, a pressure-type foam proportioning device, a balance-pressure foam proportioning type mixing device