1" Bore Sanitary Butterfly Valve with 1.5" Tri Clamp Fittings and Pull Handle1" Bore Sanitary Butterfly Valve with 1. 5" Tri Clamp Fittings and Pull Handle A butterfly valve is a valve that has a disk rotating on an axis across the diameter of the pipe to regulate flow. Butterfly valves operate similarly to a ball valve, which allows for a quick shut off. The rotating disk is positioned in the center of the pipe, and turns either parallel or perpendicular to the flow passing through it. When the valve is closed, the rotating