Drains channel water and liquids from buildings into plumbing systems. Sink drains, strainers, and traps include parts and components that allow water to flow into drains, filter out dirt and debris and reduce clogs, and prevent toxic sewer gases and odors from escaping drain lines and entering dwelling spaces. Bathtub and shower drains remove water in basins and prevent overflows. Floor drains, drain grates, and trench drains allow water to flow into drainage systems freely and have screens to filter out dirt and debris. Roof drains provide a means for rainwater and other liquids to drain on roofs before causing damage to structures. Drain interceptors keep lint and other solids from entering drain lines. Dilution tanks neutralize corrosive liquids so they can be safely discharged into sewers. Drain air vents and valves let air enter drainage systems to equalize pressure and prevent odors and gases from escaping. Cleanouts create an access point to unclog and clean sewer lines.