What is the main purpose of a plumbing trap?

The primary function of a plumbing trap is to prevent sewer gases from entering buildings. A trap holds a small amount of water, which serves as a barrier between the plumbing system and the interior of the building. This water seal effectively blocks the passage of harmful gases, such as methane and hydrogen sulfide, that can emanate from sewer lines.

The design of plumbing traps, commonly seen in fixtures like sinks and toilets, is crucial for maintaining indoor air quality and ensuring the safety of occupants. By creating a physical barrier, traps also help to minimize odors and reduce the risk of contaminants entering living spaces.

While improving water flow, increasing pressure, and filtering debris are all significant aspects of plumbing systems, they do not capture the specific purpose of a trap. The trap's primary role is its effectiveness in sealing off sewer gases, making it a vital component in any plumbing installation.