What is the primary purpose of using a wet vent system in plumbing design?

The primary purpose of using a wet vent system in plumbing design is to reduce the number of required vents. A wet vent system allows certain drains and fixtures to share a vent pipe, which can lead to a more efficient plumbing layout. By allowing a combination of drainage and venting in a single pipe, wet venting simplifies the plumbing design, decreases the amount of piping needed, and minimizes potential installation issues that arise from excessive venting requirements.

This design approach takes advantage of the principles of gravity and fluid dynamics, ensuring that as wastewater flows through the system, it also helps maintain air circulation. This dual functionality reduces the need for multiple separate vent pipes, hence creating a more streamlined system. It can also contribute to cost savings and space efficiency in building designs, making it a practical solution for many plumbing situations.