The McAlpine Z28M-NRV In-Line Non-Return Valve is a plumbing component that is designed to prevent backflow of water in a system. It is commonly used in wastewater and drainage systems to ensure that water flows in one direction only. The valve features universal connections that make it easy to install in a variety of different plumbing systems. It also has a top access feature that allows for easy cleaning and maintenance, which is important to ensure the valve functions properly over time. The Z28M-NRV model is a specific type of non-return valve that is designed for in-line use. This means that it can be installed directly into a pipe or conduit, without the need for additional fittings or connectors. Overall, the McAlpine Z28M-NRV In-Line Non-Return Valve is a reliable and durable component that can help to prevent water damage and maintain the integrity of plumbing systems. Its universal connections and top access for cleaning make it a convenient and practical choice for many different plumbing applications. ・ Prevents back flow of water ・ Must be installed in the horizontal position ・ Should only be used when there is no alternative ・ 2" Universal Connnections ・ Top Access for easy cleaning