ABSTRACT
The most extensively used nondestructive testing (NDT) method in tank construction is radiography. Conventionally, gamma radiography is performed on storage tanks. In gamma radiography, Iridium 192 source is the most commonly used source in the industry. In some specific instances such as the use of some special highly productive welding processes such as electro gas welding, some clients ask for X-ray radiography. For both of these radiography tests, the applicable code for carrying out radiography is ASME Section V. The extent of radiography and its acceptance criteria are provided in Section 8 of API650, the excerpts of which are given below.
