In any sewerage system must be air admittance valves because they do not allow the water seal to break, and they do not skip the sewer smells.
The operating principle of air admittance valves is simple: the rubber sleeve of the air admittance valve rises when in the riser build up vacuum, so air is passed into the riser, and after equalization of pressure the rubber sleeve is lowered, so sewage gas is securely locked in the pipeline.
HL air admittance valves can save performance in low temperatures (- 50 °С) and at high temperatures (up to 100 °С). However, if you install the air admittance valves on the cold attic, you will need provide with heat insulation the pipeline.
High reliability the HL air admittance valves
HL air admittance valves proved as highly reliable - they are opened and closed at least 800 thousand times without lose the tightness. All HL air admittance valves are tested for tightness and performance.
The air admittance valves is fitted with removable insect cover.