短語詞組短語backflow w preventer 回流防止器BFP Backflow Preventer 回流防止器Low -resistance backflow preventer 低阻力倒流防止器Reduced pressure zone backflow preventer 減壓回流防止閥Reduced -pressure type backflow preventer 減壓型倒流防止器backflow preventer with high -energy consumption 高能耗管道倒流防止器 返回 backflow preventer