What is the function of a Wye (Y) fitting in drainage?

What is the function of a Wye (Y) fitting in drainage?

• A. To seal a main line against leaks.
• B. To join a branch line into a main line at an angle, promoting smooth flow.
• C. To provide a cleanout access point.
• D. To reduce pipe diameter to fit smaller fixtures.

Answer: (B)

A Wye fitting is used to connect a branch line into the main drainage line at a gentle angle. This Y-shaped entry, typically at about 45 degrees, lets wastewater from the branch merge into the main flow smoothly, reducing turbulence and the likelihood of clogs. By joining the branches without a sharp turn, the main line keeps its gravity-driven slope and maintains efficient drainage. It isn’t about sealing leaks, providing a cleanout, or narrowing pipe size—those are handled by other fittings or components.

A Wye fitting is used to connect a branch line into the main drainage line at a gentle angle. This Y-shaped entry, typically at about 45 degrees, lets wastewater from the branch merge into the main flow smoothly, reducing turbulence and the likelihood of clogs. By joining the branches without a sharp turn, the main line keeps its gravity-driven slope and maintains efficient drainage. It isn’t about sealing leaks, providing a cleanout, or narrowing pipe size—those are handled by other fittings or components.