With a specially commissioned clear cap, FloPlast can now demonstrate their Air Admittance Valve (AAV) technology in action.

In the video demonstration it shows the point an AF32 valve reaches a pressure of -75 pascals (European Industry standards -150 pascals). At this stage, the AAV comes to life to ensure a balanced, odour free system.

The AAV is an important element of your soil and waste system. When wastewater flows inside a soil or waste pipe installation (for example when a WC is flushed) it generates negative pressure inside the pipe. This negative pressure can build up causing a siphoning effect, which if unchecked, would draw the water out from other waste traps within the system. This would allow odours from the drain to enter the building through the dry traps.

Traditionally to avoid siphoning occurring, soil systems were left open to draw air in, with the soil stack effectively being an open sewer. The soil stack had to be terminated above the eaves to avoid smells entering the building.

The AAV is a one-way air valve which opens to allow air to flow into the system and balance the pressure. Once balanced, the valve will then close and create an airtight seal stopping any odours entering the building. By only opening one-way, the open valve draws in clean air, but stops any foul air escaping.

Fully UKCA certified and available in 32/40/50/82/110mm, FloPlast’s Air Admittance Valves allow soil and waste systems to be terminated below the eaves line.