Installation: To install an air release valve, ensure you have a 19mm x 1/2″ BSP female iron tee at the start of your system. The air release valve screws into the 1/2″ BSP female thread of the tee piece. This valve connection is normally located after the pressure reducer assembly as this is often the highest point in the drip system. It is important to install the valve at the “highest point” in the system to allow it to work correctly. If your tap & filter is lower than the irrigated landscape, ensure your air release valve is suitably located at the highest point.