"Syphoning" in pump stations occurs when liquid is pulled by gravity from the station to the discharge point, bypassing the pump. This happens due to elevation differences between the pump station and the discharge location, leading to operational challenges. Addressing syphoning, its causes, and prevention is essential for maintaining pump station reliability and longevity.

What Causes Syphoning in Pump Stations?

The most common cause of syphoning in pump stations is where the bottom of the pump station chamber is higher than the discharge point, which allows liquid to continue to flow through the pipework when the pump disengages.

Why is Syphoning in Pump Stations Problematic?

Syphoning can cause several issues that affect both the performance and longevity of your pump station, including:

Excessive Strain on the Pump: If syphoning occurs, the pump may have to work harder to overcome the backflow, leading to higher energy consumption and possible damage to the pump.

Loss of Prime: Syphoning can lead to the pump losing its prime, meaning it will fail to pump water until the system is manually re-primed, which can cause downtime.

Flooding Risks: In some cases, syphoning can result in flooding at the discharge location if not properly managed.

Contamination or Backflow: Syphoning may allow contaminants from the discharge to flow back into the pump station, leading to system contamination.

Increased Wear and Tear: Continuous syphoning cycles increase wear on the system, reducing the lifespan of components like seals and valves.

How to Prevent Syphoning in Pump Stations

Preventing syphoning requires proper design, maintenance, and monitoring of the pump system. Here are key steps to avoid syphoning:

1. Install a Check Valve

A properly functioning check valve can prevent backflow and stop syphoning by ensuring that liquid cannot flow backward through the system.

2. Use an Anti-Syphon Valve

Install anti-syphon valves in the discharge line. These valves are designed to prevent the syphon effect by allowing air into the system when necessary, breaking the syphon and stopping unwanted backflow.

3. Ensure Proper Piping Design

Ensure that pipework is designed with an appropriate slope and elevation to reduce the risk of syphoning. Avoid overly long or complicated piping runs, and ensure that the discharge point is properly situated to prevent gravity-based syphon effects.

4. Install Air Release Valves

Air release valves allow trapped air to escape from the system, which can help maintain pressure and reduce the risk of syphoning, especially in high-elevation systems.

5. Monitor and Maintain the System Regularly

Regular inspection and maintenance of pumps, valves, and pipework can help identify issues before they lead to syphoning. This includes checking for damaged check valves, clogged lines, or worn-out seals.

Syphoning in pump stations can cause significant operational problems, from increased energy costs to equipment damage. Understanding what causes syphoning and how to prevent it is crucial for maintaining the efficiency and reliability of pump stations. By installing proper valves, ensuring correct piping design, and performing regular maintenance, you can protect your pump station from the negative effects of syphoning and keep it running smoothly for years to come. 

For more information, get in touch with the Global Water team, or explore our stormwater pump range.