Reference formula :
   • 90 DEGREES  ELBOW LONG RADIUS  
   • 8 inches (200A) miter elbow 90 degrees  

Making an elbow is very huge and helpful when the time of emergency and remedy when the spare is not available on board the ship. Pipe fabrication an elbow from straight pipe is an amazing challenge see the video is huge and helpful for those newcomers for fitter jobs on ships.