Flexcon Industries | 826 followers on LinkedIn. In 1989, Flexcon Industries started its journey to become the leading manufacturer of composite and steel pre-pressurized diaphragm expansion tanks for private well systems. With a full line of tanks for well water, thermal expansion, hydronic expansion, heating, water treatment, and constant pressure, Flexcon’s innovation, quality, and consistency has made them the go-to name in the business. Dedicated to the professional channel, Flexcon prides itself on being the sole tank manufacturer that only supports industry professionals.