To provide a smooth bend within a duct system. Fits inside the duct tubing. Use Fixture Joiners to connect elbows together.
1 April 2014
Too tight.The bend of this type of fitting has a radius equal to the diameter of the pipe. This is called a 1D bend. If at all possible avoid using these as you will lose a lot of suck and I mean a lot. Two 45 degree bends separated by a short length of pipe gives a bend equal to 2D and are a big improvement. The fit into pipe is too loose and needs 3 self tap screws as well as silicone caulk.. Cost a lot.