What is the purpose of a stack vent?

The purpose of a stack vent is to allow air pressure in drainage systems. This is crucial because it helps to maintain neutral air pressure within the drainage system, preventing the creation of a vacuum that could impede the flow of wastewater. By allowing air to enter the system, stack vents ensure that the flow of water and waste is smooth and efficient, which is essential for proper drainage. Without adequate venting, blockages can occur, leading to potential backflow and clogs.

While ventilating water supply lines, connecting multiple fixtures, and draining stormwater are important functions within plumbing systems, they do not specifically relate to the role of a stack vent. Instead, these functions are associated with different components and systems within plumbing, such as venting for fixtures or separate systems for stormwater management.