What is the primary function of a branch vent?

The primary function of a branch vent is to vent specific fixtures and maintain air pressure within the plumbing system. This is crucial because proper venting allows sewer gases to escape and prevents the buildup of pressure that could interfere with drainage. The branch vent serves to ensure that wastewater flows smoothly and efficiently through the system by equalizing pressure, which is vital for preventing siphoning of water from traps. This maintains the water seal in traps, which is important for blocking sewer gases from entering the living space. Proper venting is key in a plumbing system for maintaining functional efficiency and safety.