The Taco 5467 Heat-Gard Adapter is a compatibility component designed to connect new 54 Series valve heads to older Taco 52 and 53 Series valve bodies. It provides the proper interface between the valve head and body, allowing compatible hydronic control systems to operate with updated components. Commonly used in residential and commercial hydronic heating systems, including boilers ... https://www.partshnc.com/taco-5467-adapter-to-fit-new-54-series-heads-to-old-52-53-series-valve-bodies