Armstrong Pumps has added the ASTRO 20 and 25 circulators to its product line. These super quiet circulators, available in bronze construction with both threaded and sweat connections, were designed for use in both open and closed systems using either hot or chilled water recirculation. Typical applications include heat recovery units, ground source heat pumps, hot water recirculation, and potable water systems.Armstrong Pumps. www.armstrongpumps.com