Universal Valve to fit standard 32, 40 and 50mm solvent weld waste pipe. Allows the free entry of air into the sanitary pipework system without the escape of foul gasses into the building. It is recommended that air admittance valves are not used externally as environmental debris will affect the air tightness performance of the valve. Tested and approved for use in installations varying between -20° and +60°C (no insulation required). A1 approved in accordance with BS EN 12380 - it can be installed below the flood level of connected appliances (100mm above connecting waste system). FloPlast are the first company in the world to be awarded the Kitemark for Air Admittance Valves in accordance with BS EN 12380:2002, licence number KM512474.