How many nick break specimens are needed to qualify a procedure using flash weld technique on 24" pipe?

The correct answer, which states that 16 two-inch specimens are needed to qualify a procedure using the flash weld technique on 24" pipe, aligns with the requirements outlined in API 1104. When qualifying a welding procedure, the number and size of the nick break specimens must adhere to the specified guidelines to ensure adequate assessment of the weld's quality and integrity.

In the context of the flash welding process, the use of two-inch specimens is essential as they provide a sufficient volume of material for testing, allowing for comprehensive evaluation of the joint's mechanical properties and performance under stress. Additionally, having 16 specimens is typically deemed adequate for establishing the consistency and reliability of the welding process.

The requirements in API 1104 specify that the number of specimens correlates directly with the diameter of the pipe being welded and the welding technique employed. Smaller specimen sizes would not provide the same level of insight into the weld's characteristics, which is why opting for two-inch specimens is the appropriate choice in this scenario.

In summary, the need for 16 two-inch specimens reflects the standard practice in qualifying welding procedures to ensure thorough testing and compliance with industry standards.