What function does venting serve in plumbing systems?

Venting in plumbing systems is crucial for several reasons, primarily to maintain proper air pressure and prevent negative pressure situations. When water flows through the pipes, it can create suction that might siphon water out of traps and fixtures, leading to potential sewer gas escape into living spaces. By allowing air into the plumbing system, venting helps equalize pressure, ensuring that water and waste can flow freely without creating harmful siphoning effects. This function of venting is essential for maintaining a healthy and functional plumbing system, as it prevents traps from being emptied and helps to ensure that wastewater can move efficiently through the system.

The other responses, while related to plumbing, do not accurately describe the primary function of venting. Preventing leaks is primarily achieved through proper pipe sealing and joint fittings, while increasing water flow involves pipe diameter and design rather than venting. Filtering contaminants is a function associated with certain types of water treatment systems, not a basic function of venting in plumbing.