Class 5 Boiler Practice Exam

What percentage of the circumferential butt and miter groove piping must be examined by random radiography?

1. 1%

2. 5%

3. 10%

4. 15%

The correct answer is: 5%

The requirement to examine a certain percentage of circumferential butt and miter groove piping by random radiography is typically based on industry standards and regulatory codes. In many cases, the specified percentage is set to ensure a high level of quality assurance and integrity in welds, particularly in pressure vessels and piping systems. Choosing 5% is consistent with industry practices, which often dictate that a minimum of this percentage of the welds is examined to uphold safety standards. This radiographic inspection helps detect any potential flaws or defects that could compromise the integrity of the piping system, ensuring that they are addressed before the system is put into operation. Radiographic examinations are key in identifying issues such as gas pockets, incomplete fusion, or other discontinuities in welds. By mandating a random sampling of 5% for examination, it allows for a systematic approach to quality control without requiring complete inspection of every weld, which can be resource-intensive. The other percentages provided are either too low or too high according to usual compliance practices in the field, reinforcing why 5% is recognized as the standard for this type of examination.