Caleffi 1/2" NPT AutoFill Boiler Feed Valve

The function of the Caleffi 553542A is to automatically fill and regulate the pressure in a hydronic system to a pre-set value. Water flow to the system will automatically stop when the pre-set value is reached and fill up with more water if required. Specs and Features: 1/2" Male NPT Inlet x 1/2" Female NPT Outlet Brass construction Pressure range 3-60 PSI Factory set at 15 PSI Maximum working temperature 150 F