Flex Flanges are used in pairs to connect circulating pumps in hydronic systems.

Flex Flanges are used in pairs to connect circulating pumps in hydronic systems. Armstrong Flex Flanges rapidly isolate a circulator for service, and eliminate the need to drain and refill the entire system.
Armstrong Flex Flange is a rotating flange designed to allow maximum installation flexibility regardless of pump flange orientation. Flex Flange units are available with a spring check valve to prevent the heating medium flowing in the wrong direction in the event of gravity circulation.
The Flex Flange integrates a 2-bolt flange connection (common to small circulating pumps) with a full-port ball valve. This practical "all-in-one" design reduces the number of plumbing connections and results in a more reliable and easily-serviced hydronic system.