Sectors or elbows are transition elements with two flanges. They are designed to connect gravity pipes at an angle and are connected to each other on flanges. The tilt angle can be from 5 to 60 degrees. The combination of several sectors replaces the usual speed damper.n the process of exploitation, metal sectors, due to the friction of the grain on the surface, tend to rapidly wear out the metal. Polyurethane inserts can solve this problem.