Published on May 11, 2017
The duct elbow consists of two parts.
Angle between oblique face and longitudinal axis of each part is
B.
Angle A between axes of two parts is adjustable.
Turn the right part 180 deg. to get max A = 2B.
The more angle B is, the more duct shape differs from cylinder shape. So the elbow with more parts (3, 4, …) is recommended to reduce B.
At two connection planes (not parallel) the duct sections are round. The duct is created by connecting (lofting) those sections. So the duct middle sections are of complicated shape.
