We often fit bends to pneumatic (or other) systems from a distance. We ask the customers to send us as much information as they can provide. From that, we do our best to calculate OD, radius, and angle of the bend. Here is another example from last week. As you can see, this was an old and tired tube. All we had to work on was the inside chord, and as you’ll see from the picture below, a full picture of the bend, but only minimally helpful due to the camera location. It is always best to send us photographs at a 90 Deg angle, perpendicular to the tube. From the angle, you can see that the portion of the tube closest to the camera looks as if it has a larger OD than the rest of the tube. Also, note that this bend had apparently no tangent on the top end and an extended tangent on the bottom end.
So, we got to work and calculated our best guess on the tube. From experience, we know that a tighter radius and longer tangents solve a multitude of problems when trying to fit a bend into a system. This allows the customer to make the call on where to cut on each side.
We calculated a 120 Deg bend on a 10″ Center Line Radius with extended tangents.
So, it was nice to get a picture back from a happy customer. My only advice was to give me the coordinates of each end of the system and we could design a 3D bend in one piece.