What is the main function of the trap seal in plumbing systems?

The main function of the trap seal in plumbing systems is to provide a physical barrier against odors and gases. Traps are designed to retain a small amount of water, which creates a seal that prevents sewer gases from entering the living spaces of a building. This water seal is essential for maintaining indoor air quality and ensuring that unpleasant odors do not escape from the drainage system into the home.

The effectiveness of the trap seal relies on its ability to prevent gases from passing through while still allowing wastewater to flow through the plumbing system when needed. In scenarios where the trap seal dries out—such as infrequent use of a particular fixture—there is a risk of gases entering the space, which is why using traps in plumbing is crucial for new installations or retrofits.