Hastelloy C276 Flanges are is placed between two open flanges, which stop the flow through a pipe. Many times. They are suitable to use in various applications such as pollution control, chemical processing, waste treatment plants, and pulp and paper production. ASTM B564 UNS N10276 Blind Flange is usually used in pipe engineering, petrochemical, public services and water works. They is a solid disk used to block off a pipeline or to create a stop. It is used while adding another line onto an existing pipeline or when a new valve is being added.