An important function of our check valve is the so-called anti-odour flap. When bad odours emanate from the sewer, our Stop Silent SL13 valve is quickly installed and reliably solves this problem. This problem occurs especially in summer when the sewage disposal system warms up and the unpleasant smell spreads into the cellar and garage. Channel gases reach the surface through inspection wells due to a so-called stack effect. In addition, our anti-odour valve provides reliable protection against backflow with a back pressure of up to 0.5 bar. Another function of this non-return device is a nose flap, preventing small animals from entering the sewer system.