What is a trap seal in plumbing?

A trap seal in plumbing refers to the vertical distance between the bottom of a trap and the liquid level in its outlet. This is a critical component of traps in plumbing systems, as the trap serves to prevent sewer gases from entering the living space while allowing wastewater to be drained away. The trap maintains a seal of liquid, which can vary in height depending on the design and use of the plumbing fixture.

The trap seal is essential for the proper functioning of plumbing fixtures. If the trap seal evaporates due to lack of use or lack of water, it can result in foul odors and harmful gases infiltrating the indoor environment. So, maintaining an adequate trap seal is vital for both health and safety in plumbing systems.