What is the purpose of a P-trap?

A P-trap, commonly found in plumbing systems, serves a critical function in residential and recreational vehicle settings. Its primary purpose is to prevent unpleasant gases and odors from the sewer system from entering the living space. This is accomplished by maintaining a small amount of water in the curved section of the trap, which acts as a barrier. When water flows through the trap, it creates a seal that stops sewer gases from escaping back into the RV or home environment.

This design is particularly important in areas such as kitchens, bathrooms, or any space with plumbing fixtures. By effectively blocking these unwanted gases, the P-trap contributes to maintaining a healthy and pleasant atmosphere within the living space. Understanding this function is essential for any technician working on RV plumbing systems, as it directly impacts both safety and comfort for the occupants.