Understanding Air Admittance Valves And Their Installation

If you want to add a new bathroom to your home, then you will obviously need a great deal of new plumbing lines added to the space. In many cases, your plumbing contractor will also advise for the installation of new plumbing vent. If this is not an option, then an air admittance valve can be secured instead. Keep reading to learn about these valves.

What Is an Air Admittance Valve?

Vents are often added to homes to allow air into the drainage system. This allows for the free flow of wastes and the reduction of a vacuum in the system that can lead to backflow issues and the accumulation of sewer gas. And the majority of vents are installed close to bathrooms and run all the way up to the roof. Depending on your plumbing system, one or two vents may be installed. 

Once a home has been fully completed, it can be difficult to add an additional vent to the plumbing system, especially one that travels all the way to the roof. To cut down on installation issue, air admittance valves are used instead. These valves are small caps that are added to drainage lines just after the trap. The valves open up as pressure builds in the waste pipe and air is forced into the pipe through one or several small openings. Pressure then reduces, and the waste moves down the length of the pipe to empty into the sewer.

How Are Air Admittance Valves Installed?

Your plumbing professional will look at the drains in your bathroom and decide whether one or several of the valves are required. While one valve can add air to several different lines and fixtures, one valve may be added per drain. Typically, the toilet requires more pressure regulation than many of the other drains, so it will often get its own valve. 

The valve must sit above the trap; otherwise, water and gas may accumulate by the valve and make it difficult for the part to allow air into the system. For this reason, the valve is often installed on the top of the larger sewage line that connects to the other pipes in your home. To ensure the height of the valve, a long piece of vertical pipe may be installed as well, and the valve is secured on top.

Valves may be installed in the walls or they may be added under a sink or in another region. Since the valve may require maintenance, it is wise to ask for installation in an area that is easy to get to.