The Belimo F6, F7 Series butterfly valves fulfill the requirements of commercial and industrial HVAC applications requiring positive shutoff for water. Applications include chiller isolation, cooling tower isolation, change-over systems, large air handler coil control and bypass, and various water distribution and storage systems. The F6 assemblies are two-way and the F7 are three-way flow patterns. Undercut disc assemblies, designated by "HDU" in the part number have a maximum close-off of 50 psid, and full-cut models, designated by "HD" part number, have full 200 psid close-off rating. Small size valves are available with economical Belimo rotary actuators and all sizes are available with industrial grade, NEMA 4 actuators, to meet most application requirements. Other sizes, assembly combinations, connection types, and materials of construction are available.