Pressure vessels welds inspection

Pressure vessel thickness varies widely, from a few millimeters for small, low-pressure applications to significantly larger values, such as the 122 mm (4.8 in) shell thickness for the High-Temperature Engineering Test Reactor’s pressure vessel. It is thus necessary to have ultrasonic techniques that can accomodate this entire thickness range. Nozzle inspections present also a challenge due to accessibility issues, geometric challenges like varying curvature, particular weld profiles and potential interference from internal components.

Material wise, pressure vessels can be made out stainless steel and be cladded making ultrasonic inspection more complicated.

Angle-beam UT, PAUT, and TOFD remain the cornerstone ultrasonic techniques for the inspection of pressure vessel welds. They have long been recognized for their reliability in detecting flaws and ensuring compliance with industry codes. Building on this foundation, advanced full matrix capture and total focusing method techniques are increasingly adopted, particularly for critical applications and fitness-for-service evaluations where enhanced data quality and inspection confidence are essential.

Semi-automated scanners for accessible welds and fully automated crawlers for large vessels or restricted areas guarantee accurate probe positioning, stable coupling, and complete weld coverage with minimal operator dependence. This ensures inspection repeatability, reduces variability between operators, and improves productivity even in complex field conditions. Inspection strategies can be further adapted with standard or custom-built PAUT and TOFD probes to provide optimal coverage across both carbon steel and stainless steel welds. Beyond these established approaches, next-generation methods such as pitch-catch TFM with PWI and PCI mixing, combined with mode fusion, deliver significant improvements in detection capability and characterization. These techniques provide higher resolution imaging, reduce interpretation uncertainty, and make data easier to analyze. As a result, inspectors benefit from clearer indications, faster evaluations, and greater confidence in their decisions.

EIG brings these advanced ultrasonic inspection technologies to the field through the SPIKE phased-array electronics platform, EK31 probes, and the VENOM scanner family. Together, these solutions enable high-performance weld inspection strategies that combine state-of-the-art imaging with practical deployment tools, supporting safer, more efficient, and more reliable pressure vessel operation.