In plumbing systems, what is the main purpose of a vent?

The main purpose of a vent in plumbing systems is to prevent the backflow of gases. Vents allow sewer gases to escape to the outside atmosphere, which helps maintain safe and healthy air quality within the building. When fixtures such as sinks, toilets, and showers are drained, the water creates a vacuum in the pipes. Without proper venting, this vacuum can lead to a situation where backpressure can push sewer gases back into the living spaces, posing health risks.

By providing an unobstructed pathway for air to enter the plumbing system, vents help to equalize the pressure within the pipes, ensuring that wastewater flows smoothly downward without disrupting the trap seals that prevent odors from escaping. This function is critical for effective drainage and sanitation within any plumbing installation, showcasing the vent's role in health and safety standards.