What is the purpose of a trap in plumbing systems?

The purpose of a trap in plumbing systems is to prevent sewer gases from entering the building. A trap is a curved section of pipe that retains a small amount of water at all times. This water creates a seal, effectively blocking the escape of foul odors and toxic gases that can come from the sewer system. By maintaining this water barrier, traps play a crucial role in ensuring indoor air quality and protecting the health of occupants.

While traps may assist in other functions such as helping in drainage and potentially storing some water, their primary function centers around safety by preventing harmful sewer gases from infiltrating living spaces. This is a critical aspect of plumbing design, especially in residential and commercial buildings, as it directly impacts hygiene and comfort for those who use the facilities.