Watts Series N170, N170L Hot Water Extender Tempering Valves are used in commercial and industrial applications to mix cold and hot water to extend capacity of water heater, storage tanks and hot water boiler tankless heaters. It features bronze body construction with threaded connections, stainless steel disc, and copper thermostat assembly. Series Watts N170, N170L features a double thermostat design that combines two thermostats in one to provide response to changes in water temperature passing through the mixing chamber. Series Watts N170 valve temperature range: 130°F to 180°F. Series Watts N170L valve temperature range: 100°F to 130°F. Maximum Pressure: 150psi (10 bar).