Airvac
How Airvac Works
How Airvac Works
Airvac is a vacuum sewer system that's an ecological alternative to areas where failing septic tanks are causing pollution or where traditional gravity sewer systems are aging. They specifically work well in areas with subsurface difficulties. (For example: high groundwater tables, sandy and unstable soils, rocky terrain, restricted construction conditions, acid sulfate soils (A.S.S), or sensitive eco-systems.)
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With a vacuum sewer system, vacuum pumps maintain continuous vacuum pressure on the system. In addition, there are vacuum valves located at each sewage input point that seals the system. When these valves are activated, differential pressure propels the wastewater through the piping to the vacuum station.
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As an illustration, imagine sucking on a straw filled with water and your finger is covering the end of the straw. When you remove your finger, the water shoots into your mouth. Vacuum sewer systems work in a similar fashion. In this scenario, your mouth is acting as the vacuum station and your finger is acting as the vacuum valve.
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Another key point. Because there is constant vacuum pressure on the system, wastewater never leaks into the ground. Although rare, if a pipe should get punctured or cracked, the vacuum will continue to “suck in” instead of “leak out”. For this reason, vacuum sewer systems are significantly better for the environment.
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See the step-by-step guide below that explains how a vacuum sewer system works.
1. Gravity Carries Wastewater to the Valve Pit
Firstly, a gravity line carries wastewater from a customer's home to the sump portion of the valve pit package. In most cases, one valve pit package will service three homes and is typical located in a right-of-way.
4. Vacuum Pumps Cycle On and Off
Fourthly, vacuum pumps cycle on and off as needed at the vacuum station (vacuum pump modulation improves this functionality) to maintain a constant level of vacuum on the entire collection system.
2. The Vacuum Valve Opens and Empties the Sump
Secondly, the vacuum valve opens when ten gallons of wastewater collects in the sump portion of the valve pit package. Differential pressure then propels the wastewater into the vacuum main.
5. Wastewater Enters the Collection Tent
Fifth, wastewater from the vacuum main enters the collection tank fills until it reaches a predetermined level. The wastewater levels are managed by a control panel located in the vacuum station.
3. Wastewater Travels Through The Vacuum
Thirdly, wastewater travels at 15 to 18 feet per second in the vacuum main to the vacuum pump station. The vacuum main piping is laid in a sawtooth fashion to ensure adequate vacuum levels are maintained at the end of each line.
