Cast Iron Taco 008-F6-3IFC Circulator Pump with Integral Flow Check (IFC) is designed to reduce installation costs when zoning with “00” circulators on hydronic or radiant heating, hydro-air fan coils or closed-loop solar heating systems. A built-in Integral Flow Check (IFC) of the Taco 008-F6-3IFC eliminates the need for purchase and installation of an additional flow check valve.