What is a plumbing vent?

Sanitary drains require a few key elements to flow properly: the correct grade, adequate pipe sizing, and of course, airflow. So, what is a plumbing vent, and why is it so important? A plumbing vent allows air to enter the system when the line is flushed and releases bad sewer smells to the atmosphere, helping the drain “breathe” and keeping your plumbing flowing smoothly. Across all types of projects, plumbers install various vents, but the most common sewer drain will have a main vent performing these essential functions.