Water trap for sanitary appliances

A generally U-shaped water trap for sanitary appliances, said water trap having an inlet opening and an outlet opening and comprising a housing having:

• an upper portion provided with the inlet opening adapted to receive an outlet pipe of the sanitary appliance;
• a central portion adapted to be connected to the upper portion provided with a cylindrical passing through space, the outlet opening being situated in a lower extension of the central portion and adapted to be connected to an evacuation pipe of a drainage system, the central portion further including a valve housing situated in an upper part of the central portion and incorporating an air admittance valve;
• a lower portion in which the water trap is formed and which is connected to the central portion, the lower portion having a part thereof of an outer shape of an oblong cup formed by two intersecting cylindrical walls but wherein parts of the cylindrical walls which normally intersect are left out to create an open intersection area;
• and
• a separation wall extending downwardly from a lower surface of the central portion into the lower portion for forming at least a part of a U-shaped seal in the water trap, the separation wall being positioned in said intersection area, the separation wall having a lower part and being sized to leave an area between the bottom of the part of the lower portion with the outer shape of an oblong cup and the lower part of the separation wall sufficient to allow waste water flow to be evacuated through the outlet opening, the U-shaped seal being formed by water present in the lower portion between an upper level of an overflow rim of the outlet opening and the lower part of the separation wall,
• wherein the outlet opening of the central portion is provided an horizontal partition wall which is situated about the center line of the outlet opening and divides said outlet opening into separate conduits, said separate conduits comprising one upper conduit above the partition wall for allowing inlet air to flow from the air admittance valve and one lower waste water conduit situated beneath the partition wall for allowing the waste water flow to be evacuated through the outlet opening towards the drainage system.