The McAlpine CONVALVE-125P Convalve Non-Return Valve is a plumbing fitting designed to prevent backflow in a pressurized hot water system. It is manufactured by McAlpine, a UK-based company that specializes in plumbing products. The CONVALVE-125P model features a ¼" plain tail inlet and a ¼" universal outlet, which allows it to take pressure-relief discharge from pressurized hot water cylinders. The non-return valve design prevents water from flowing back into the cylinder, which can help to protect the system and prevent damage from overpressure or overheating. The valve is constructed of high-quality materials and is designed to provide reliable and long-lasting performance. The ¼" universal outlet is compatible with a range of different plumbing systems, making it a versatile option for different types of installations. Overall, the McAlpine CONVALVE-125P Convalve Non-Return Valve is a reliable and effective solution for preventing backflow in a pressurized hot water system. It is suitable for use in both residential and commercial plumbing systems and can help to prevent potential damage and water wastage.