The 2” with MNPT kinetic air relief valve allows large volumes of air to escape from the irrigation pipe as the system is being filled when it is turned on. It also allows air into the pipe when the system is turned off. As the pipeline fills, water enters the air relief valve and raises the float to shut the valve. When the irrigation system turns off, the float drops, allowing air to enter the pipe and preventing possible vacuum in the pipe, pipeline collapse, and valve and drip emitter breakage. Air Vacuum Relief Valves offer an efficient means to fill and drain pipelines, providing full protection to the irrigation system components.
The air relief valve installed with a drip line or drip tape for sub-surface installations allows air into the drip line or zone when the system it is not operating. It is not required for above the surface installations. The air relief valves can reduce the chance of water hammer damage caused by a sudden reversal of water flow. The air relief valve allows air to escape during system start-up and prevents air restrictions within the system.
In any irrigation system trapped air bubbles can damage pumps (via cavitation) and disrupt the flow rate and pressure in the system. The two main reasons we suggest installing an air relief valve in an irrigation system are:
1.They provide a means of releasing air from the drip line when the system is turned on and can eliminate any air pockets.
2.They allow air to freely enter the system when it is shut down, ensuring a vacuum does not draw debris into the drip line via the drip emitter outlets. This condition is known as "suck back". Suck back can cause the drip line to collapse or draw in dirt and debris that clog the drip emitters.
To install an air relief valve, ensure you have a 2" FNPT tee at the highest point along the pipeline, upstream of the valves manifolds, near the pump or filtration stations. The air relief valve should thread into a 2" male pipe thread. It is important to install the air relief valve at the highest point of the system layout or near the pump and filtration stations to allow it to work correctly. If your water inlet and filter are lower than the irrigated landscape, ensure your air relief valve is suitably located at the highest point.