Rationality of Density Requirement for Radiographic Testing of Weld Seam at the Double SAW Pipe Ends

Density is one of the important indicators to measure film quality. There are different requirements for density in existing pipe manufacturing standards and their cited testing standards. Therefore, disputes are caused by different density requirements in the actual radiographic testing of weld seam at the double SAW pipe ends. Through thorough analysis and investigation by combination of radiographic testing theory and actual application, it was pointed out the lack of rational strictness of density requirements in standard DEP 31.40.20.37:2013 as well as the irrational leniency of density requirements in GB/T 9711-2011 and other standards. At last the relatively reasonable guideline for density requirements was summarized and proposed.