A fixture trap must flush completely and be what?

A fixture trap must flush completely and be self-cleaning to ensure efficient operation and maintenance of the plumbing system. Self-cleaning traps are designed to prevent the buildup of debris or waste material, which can lead to clogs and the need for frequent cleaning or repairs. This feature is essential for maintaining hygiene and preventing odors, as it allows the trap to effectively remove waste during each flush. Traps that do not have self-cleaning properties may require additional maintenance, thereby increasing the likelihood of plumbing issues over time.

In contrast, while non-corrosive traps can be advantageous in certain situations, they do not address the fundamental need for the trap to remain clear of blockages. Adjustable traps may provide some flexibility in installation but do not inherently ensure that the trap remains clean. The term "lifelong" implies durability but does not guarantee cleanliness or effective waste removal throughout the trap's lifespan. Thus, self-cleaning is a critical characteristic needed for the efficient functioning of a fixture trap.