Which statement correctly describes the functionality of a Venturi tee in plumbing systems?

The statement highlighting that a Venturi tee increases water velocity while decreasing pressure accurately describes its functionality within plumbing systems. A Venturi tee operates based on the principle of fluid dynamics known as the Venturi effect. When water enters a narrower section of the tee, it speeds up, which results in a reduction in pressure at that point.

This increase in velocity and decrease in pressure are crucial for various applications in plumbing, such as ensuring the proper flow of fluids and aiding in the drainage system's efficiency. The design benefits not only help in moving water through systems but also facilitate the removal of air or gas trapped in the plumbing lines, contributing to an effective and efficient plumbing system.

The other choices do not accurately describe the primary function of a Venturi tee. For example, while it might indirectly assist with venting in systems, its main purpose is not to serve solely as a junction point for venting gases. Instead, the Venturi tee is more focused on the flow dynamics of liquids. Thus, the answer reflects a fundamental principle of fluid flow that is essential for efficient plumbing design and function.