This 1-1/2 in dual check valve is designed to prevent the reverse flow of polluted water from residential fire sprinkler systems from entering into the potable water supply. It consists of a bronze body, silicone seat disc, union seals and captured stainless steel springs. This valve is easy to maintain and service. The minimum working pressure is 10 psi (69 kPa). The maximum working pressure is 175 psi (12.06 bar).