The Grundfos 00596630 Check Valve is a genuine OEM replacement designed for use with UP(S) circulator pumps. It prevents backflow, ensuring that water moves in the correct direction for optimal system performance and efficiency. Built with high-quality, durable materials, this valve offers long-lasting reliability and resistance to wear in residential and commercial applications. Engi... https://www.partshnc.com/00596630-grundfos-check-valve-for-ups