Z TORK Automation Co. is a leading manufacturer, supplier and exporter of Centric Butterfly Valves in Ahmedabad, Gujarat, India. Centric Butterfly Valve (also known as a concentric or resilient-seated butterfly valve) is a type of quarter-turn rotary valve where the disc is positioned in the center of the valve body, and the shaft (or stem) passes through the center of the disc. The seating is typically made of elastomeric or rubber materials, which provides a tight shut-off.