What is the function of a plumbing vent in a drainage system?

The function of a plumbing vent in a drainage system is to allow air to enter and prevent siphoning. Vents are essential components that connect to the drainage system to provide atmospheric pressure, ensuring that as water flows through the pipes, air can replace the water that leaves the system. This prevents the creation of negative pressure, or siphoning, which can lead to slow draining and even blockages in the pipes.

By allowing air to enter the drainage system, vents help maintain proper flow rates and ensure that wastewater can move freely without creating a vacuum that could impede drainage or lead to malodorous sewer gases being drawn into the building. Proper venting is crucial for maintaining the efficiency and safety of the plumbing system, making it an integral part of plumbing design according to the National Plumbing Code of Canada.