T9074-AS-GIB-010/271 Rev 1
CHAPTER 3 RADIOGRAPHIC TESTING
3.1 INTENDED USE. The radiographic test method is primarily used for the detection of discontinuities through the volume of welds and castings in most types of material and in a variety of geometric configurations. Requirements for the use of digital computed radiography for the detection and measurement of pipe corrosion and erosion are attached as Appendix A. 3.2 DEFINITIONS. The standard terminology for radiographic nondestructive examination as described in ASTM E1316 shall apply to this section, except as noted below. 3.2.1 Material Thickness (T m ). The material thickness (T m ) is the nominal thickness or actual thickness, if measured, of the strength member, and does not include reinforcements, backing rings or strips. The strength member is defined as the thinner of the sections being joined. 3.2.2 Maximum Effective Radiation Source Dimension. The maximum source or focal spot dimension projected on the center of the radiographic film. For example, a cylindrical isotope source whose length is greater than its diameter will have a greater effective radiation source dimension when oriented coaxially in the center of a pipe for a panoramic exposure than when the axis of the source is positioned at right angles to the pipe. 3.2.3 Multiple Film Technique. A procedure in which two or more films, of the same or different speed, are used in the same film holder and exposed simultaneously. 3.2.4 Specimen Thickness (T s ). The total thickness to be radiographed including, if present, reinforcements, backing rings, or strips. This is the thickness upon which the source-to-film distance (SFD) is based. 3.3 GENERAL REQUIREMENTS. The radiographic method of testing is used for determining the presence of discontinuities in all ferrous and nonferrous metals. Radiographic inspection specified herein is intended to apply to all items requiring radiographic inspection in compliance with applicable specifications, drawings, contracts, or purchase orders, and one of the following shall be used: a. X-ray machine. b. Iridium-192. c. Cobalt-60. d. Selenium-75. e. The use of other radiation sources requires specific NAVSEA approval.
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