Which of the following is not considered a trap?

The correct answer is that the Tee-trap is not considered a trap in traditional plumbing terminology. A trap, in plumbing, is a device that holds a small amount of water to prevent sewer gases from entering a building while allowing wastewater to flow through.

The U-trap, P-trap, and S-trap are all functional types of plumbing traps designed for specific purposes. The U-trap has a U-shaped bend that retains water, creating a seal against gas. The P-trap, which is the most commonly used trap, has a similar purpose but is designed in a configuration that makes it easier to install under sinks. The S-trap is typically used in toilet applications where the outlet pipe runs directly to the sewer line.

The Tee-trap, while it may resemble other traps in its function, is not widely recognized or utilized in plumbing practices. Traps like the U, P, and S have established purposes within plumbing codes and applications, making them standard features in drainage systems, whereas a Tee-trap does not fit this category and lacks the same practical use in functional plumbing systems.