The Schneider Electric VB-7211-0-4-4 valve, formerly Barber Colman, is a 1/2-inch, normally open (N/O) union valve. It's engineered for precise fluid control in HVAC systems. With a 4.4Cv flow coefficient, it regulates liquid flow efficiently. The "union" design facilitates easy installation and maintenance. https://www.partshnc.com/12-no-44cv-union