Irrigation Lines: Airlock Impact and Management

Airlock in irrigation systems is a common problem that can hinder the efficiency of water distribution by creating blockages with trapped air pockets in the lines. If not addressed, this issue can lead to significant problems despite seeming minor.

Air can enter an irrigation system through various means, such as leaks, inadequately sealed joints, or during the initial filling of water. Also, as water moves through pipes of different heights, air will naturally rise and collect at the highest points due to its lighter weight compared to water. If air is not effectively removed, it can cause blockages that hinder water flow, especially in areas with varying elevations where air can become trapped.

The presence of airlocks in an irrigation system can have various negative impacts. It disrupts the uniform distribution of water which causes some areas to receive less water while others may be over-watered. This inconsistency can harm crop health and yield, as plants require a consistent water supply for optimal growth. Additionally, airlocks can lower the system’s overall pressure, requiring water pumps to work harder to clear these obstructions. This increased strain can lead to higher energy consumption, greater operational costs, and potential mechanical failures that necessitate expensive repairs or replacements. 

To prevent airlocks, it is important to ensure that the irrigation system is designed and installed properly. This includes meticulously sealing all joints and connections to prevent air infiltration. Filling the system with water during the initial setup is also essential to reduce the presence of air. The installation of air relief valves at strategic points in the system is also an effective method for managing airlocks, as these valves automatically release trapped air to maintain a steady water flow. In certain systems, manually releasing air by opening specific valves can help eliminate air pockets. Designing the system with gradual slopes and avoiding sharp high points can prevent air entrapment from occurring in the first place.

Regular maintenance and inspection of the system are essential to identify and repair leaks promptly and ensure all components are functioning properly, thus reducing the risk of airlock occurrence.

References:

Air vent vacuum relief in irrigation. (n.d.). Drip Depot DIY Irrigation Support. https://help.dripdepot.com/support/solutions/articles/11000064574-why-you-need-air-vent-vacuum-relief-in-your-irrigation-system (image)

Reynolds, C., & Yitayew, M. (1995). Low-head bubbler irrigation systems. Part II. Air lock problems. Agricultural Water Management, 29(1), 25–35. https://doi.org/10.1016/0378-3774(95)01189-7 

Wan, W., Li, C., & Yu, Y. (2017). Investigation on critical equilibrium of trapped air pocket in water supply pipeline system. Journal of Zhejiang University. Science A, 18(3), 167–178. https://doi.org/10.1631/jzus.a1600325