What is a combination waste and vent system designed to do?

A combination waste and vent system is specifically designed to facilitate the horizontal wet venting of fixtures. This system allows both waste and venting functions to occur within the same pipe, which can save space and simplify plumbing layouts. When multiple fixtures are connected to a common drain line, the design ensures that the wastewater flows adequately while still allowing air to enter the system through the same pipe. This helps maintain equal air pressure within the drain system, preventing siphoning and the potential for sewer gas entry into the living spaces.

Using a combination waste and vent system can also effectively minimize the number of pipes needed in a plumbing installation, reducing material costs and installation complexity. Properly designed, this system adheres to plumbing codes that govern the installation and functionality of drainage systems, ensuring safety and efficiency.