一、Structure and purpose

Used in the living and fire-fighting merged water supply system It supplies living water at normal condition and．in case of a fire，automatically close the living water and open the fire-fighting one to make it surely enough，and then when fire-fighting water stops and the pressure is reduced，resets the living wa-ter automatically．Thus making the system no need to set an individual fire-fighting water supply pipe network and both engineering construction cost and daily water used quantity greatly saved.It features sensitive control,safety,reliability,simple debugging and long duration

四、Schematic diagram of installation

Note：Either elastic seat ring sealed gate valve of butterfly valve can be selected in the schematic diagram of installation.Recommended to select the butterfly valve in case of≥DN350