If You need help measuring the centerline radius of an present elbow, it's best to talk to an elbow manufacturing expert to make sure you get the right measurements and the best solution for your needs. Pipe fitter instruction, metal fitter coaching, piping and structural fitter fabricator teaching the best https://www.malleableiron-pipefitting.com/industry-knowledge/how-to-find-elbow-center-of-pipe.html