Trap and drain assembly for draining waste liquids while blocking odors

A trap assembly for draining waste water toward sewer pipes while blocking back flow of odors comprising:

• a U-shaped liquid trap for containing a waste water and a sealant liquid, wherein the specific density of said sealant liquid is lower than the specific density of said waste water, causing said sealant liquid to float above said waste water, and wherein said U-shaped liquid trap having an interior, a receiving opening for receiving said waste water, an outlet pipe for connecting to a sewer line, and a release opening near a bottom of said interior, wherein said interior further comprising a first compartment and a second compartment, wherein said first compartment and said second compartment are connected through at least one relief hole, and wherein said first compartment is connected to said sewer line through said main flow pipe, and wherein said release opening is at the bottom of said second compartment;
• a release pipe connecting said release opening to said sewer line;
• a valve mounted within said interior in proximity of said release opening, said valve configured to occlude said release opening when the buoyancy from said sealant liquid and said waste water in said interior is below a predetermined level, and wherein said valve is in an open position when the buoyancy of said sealant liquid and said waste water is at least equal to said predetermined level.