What is the vertical distance between the dip and crown weir of the trap?

The vertical distance between the dip and crown weir of a trap is referred to as the trap seal. This distance is crucial because it represents the amount of water that remains in the trap to create a seal that prevents gases from the sewer system from entering the living space. The trap seal is designed to maintain this barrier while allowing wastewater to pass through the plumbing system.

In sanitary drainage systems, the trap seal helps to ensure proper function, as an insufficient seal can lead to odors and potential health hazards. Understanding the concept of trap seal is essential for anyone involved in sanitation design and installation because it helps maintain hygiene and proper system operation. The other terms listed do not pertain to the specific measurement represented by the distance between the dip and crown weir of the trap.