Air-admittance valves are mechanical valves that equalise the pressure in the pipe system. In the case of negative pressure in the pipe system, the ventilation valve opens and fresh air is sucked into the pipe until the pressure is equalised again. This prevents the trap being sucked dry, which would enable sewer gases to enter the room. As long as the pressure is equal, the ventilation valve remains closed, and in the event of overpressure, it seals the system.
Air-admittance valves ensure long-term and problem-free functionality even without maintenance. Dallmer impressively combines form and function. The cover plates can be individually painted in-situ or chrome-plated so that, as well as delivering technical quality, the valves also harmoniously blend with the bathroom landscape.