The McAlpine Waste Valve 1.1/4" Tundish Macvalve-3 is a plumbing component used in waste and drainage systems. The valve is designed to allow waste water to flow out of a plumbing system while preventing gases and odors from entering the living space. The valve includes a tundish, which is a small device that allows air to enter the system and prevents the waste water from siphoning back into the plumbing fixtures. The Macvalve-3 model is specifically designed for use with a 1.1/4" waste pipe. It is made by McAlpine, a leading manufacturer of plumbing products in the UK. Installation of the McAlpine Waste Valve 1.1/4" Tundish Macvalve-3 should be done by a qualified plumber, following local codes and regulations. It is important to ensure that the valve is installed correctly to prevent leaks and other issues in the waste and drainage system. ・ 1¼" outlet ・ BSP female inlet nut x universal compression outlet ・ Supplied with Tun Dish Adaptor - 1¼" BSP male thread x 22mm Universal inlet ・ Can be used to take the discharge from a pressure relief valve on an unvented domestic hot water storage system. Please refer to guidance notes in approved Document G3 of the Building Regulations ・ Membrane opens under water pressure to allow discharge to flow freely and then closes to form a seal to prevent foul odour or sewer gas entering the building