The standard describes dimension ratios (DRs) 14, 18, and 25 for nominal pipe sizes ranging from 4 in. (100 mm) through 12 in. (300 mm).
Thank you Contractor Campus for providing me with this Pdf file. A lot of the information here was on my exam.Joanna Gonzalez
This book has a lot of information, it was so much help during the exam ! Plus it was in perfect condition when I received it !
Jess Marie