This Navien 90 degree flue bend, also known as a 90-degree elbow, is a component used in flue systems to change the direction of the flue pipe by 90 degrees. This type of bend allows the flue to navigate around obstacles, change its routing path, or connect to appliances and other sections of the flue system in a more flexible manner.

Used to change the direction of the flue system, typically either horizontally or vertically. This is essential for routing the flue pipe around architectural features, through walls, or up through ceilings and roofs.

In essence, a 90-degree flue bend is a crucial component in the design and installation of flue systems, providing the necessary flexibility to adapt to building layouts and ensuring that exhaust gases are safely and efficiently vented to the exterior.