An Authorized Pressure Vessel Inspector (API) plays a critical role during routine inspections under API-510.Their responsibilities include assessing the physical condition of the vessel, ensuring compliance with safety regulations, and verifying that the vessel operates within the specified parameters. Inspectors are required to conduct thorough examinations, including both external and internal checks, using appropriate non-destructive testing methods. They must also review maintenance and repair records and ensure that any anomalies found during inspections are addressed promptly. The API's role is crucial in certifying that vessels continue to operate safely and efficiently, adhering to the regulatory requirements outlined in API-510.

Welds have rough surface compared to parent material and hence the penetrant can seep inside the weld discontinuities easier and faster. see ASME V; Table T-672 Minimum Dwell Times; pp. 219