In a trap diagram, the letter B most likely labels which component of the trap?

In a trap diagram, the letter B most likely labels which component of the trap?

• A. Inlet
• B. Weir
• C. Outlet
• D. Vent

Answer: (B)

In a trap diagram, the important feature is the edge where the trapped water meets the outlet to the drain. That top edge, where the water level is held back and then flows over into the outlet, is the weir. The label placed at that edge identifies the weir because it marks the boundary between the trap’s water seal and the downstream flow. The inlet is where water enters the trap from the fixture, the outlet is the pipe leaving the trap toward the drain after it passes the weir, and the vent is the connection that allows air in to prevent siphon. Since the letter sits at the edge where the water goes over into the outlet, it corresponds to the weir.

In a trap diagram, the important feature is the edge where the trapped water meets the outlet to the drain. That top edge, where the water level is held back and then flows over into the outlet, is the weir. The label placed at that edge identifies the weir because it marks the boundary between the trap’s water seal and the downstream flow. The inlet is where water enters the trap from the fixture, the outlet is the pipe leaving the trap toward the drain after it passes the weir, and the vent is the connection that allows air in to prevent siphon. Since the letter sits at the edge where the water goes over into the outlet, it corresponds to the weir.