What is the purpose of a vent pipe in a plumbing system?

The purpose of a vent pipe in a plumbing system is to allow air into the system to prevent siphoning. Vent pipes are an essential part of a plumbing system because they help ensure that the wastewater flows smoothly and that there is proper drainage. When water is discharged from fixtures, the vent pipe provides a necessary air supply that helps to equalize pressure and prevents the formation of vacuums. This is critical because if a vacuum were to form, it could cause siphoning, where water is drawn out of traps and could allow sewer gases to enter the living space. Therefore, the vent pipe plays a crucial role in maintaining the functionality and safety of the plumbing system by ensuring that the systems work efficiently without creating negative pressures that could disrupt their operation.