The McAlpine CONVALVE is an in-line vertical non-return valve that is designed for use with pipes that have an inlet and outlet connection of 19/23mm. This valve is typically used to prevent the backflow of water or other fluids in a piping system. The valve is made from high-quality materials and is designed to be durable and long-lasting. It features a compact and lightweight design that makes it easy to install and use. The valve is also easy to maintain and clean, which helps to ensure that it continues to function properly over time. The non-return valve works by allowing fluid to flow through the pipe in one direction only. If there is a backflow of fluid in the opposite direction, the valve will automatically close to prevent the fluid from entering the system. This helps to prevent contamination of the fluid and ensures that the system remains safe and functional. Overall, the McAlpine CONVALVE is a reliable and effective non-return valve that is ideal for use in a wide range of piping systems. Whether you are installing a new system or upgrading an existing one, this valve is a great choice for ensuring the safety and functionality of your piping system. ・ 19/23mm Inlet and Outlet ・ Prevents waste water from sanitary pipework entering a condensing boiler ・ Receives the discharge from a condensing boiler ・ Conforms to BS 6798:2009 and Building Regulations Approved Document H