The Utica-Dunkirk VR-001.01 is a 3/4-inch, 30 PSI pressure relief valve designed to protect compatible hydronic heating systems from excessive pressure. It works by automatically opening when system pressure reaches its rated limit, releasing excess pressure and helping prevent damage to boilers and related components. This relief valve is commonly used in Utica-Dunkirk boilers and ot... https://www.partshnc.com/vr-00101-utica-dunkirk-34-30-relief-valve