[4C1] On-stream weld integrity assessments with high-temperature UT
T Stevenson¹, G Mugford² and S Kenny²
¹Ionix Advanced Technologies Ltd, UK
²Eddyfi Technologies Ltd, UK
Ultrasonic time-of-flight diffraction (TOFD) is a popular method widely used in the petrochemical, energy and other industries for the in-service detection and characterisation of weld defects, such as root corrosion, porosity, inclusions and cracks. However, with increasing demand for on-stream measurements, conventional TOFD is limited due to the temperature at which these probes can operate, often causing failure of the transducer or causing noise in the wedges to mask the ultrasound signal.
Presented here is an evaluation of high-temperature TOFD transducers, with integrated wedges, mounted onto a modified scanner for high-temperature encoding such that the whole system is suitable for weld inspections at continuous elevated temperatures up to 350ºC. Shown with high-temperature couplant and connected to a commercially available flaw detector set, this paper establishes the performance and detection characteristics of weld root corrosion and common defects/damage mechanisms in carbon steel piping circuit welds inspected at >200ºC, without shutdown or isolation of the asset under test, and presents requirements for compensation due to the inherent changes in steel velocity and attenuation with increasing temperature.
Presented here is an evaluation of high-temperature TOFD transducers, with integrated wedges, mounted onto a modified scanner for high-temperature encoding such that the whole system is suitable for weld inspections at continuous elevated temperatures up to 350ºC. Shown with high-temperature couplant and connected to a commercially available flaw detector set, this paper establishes the performance and detection characteristics of weld root corrosion and common defects/damage mechanisms in carbon steel piping circuit welds inspected at >200ºC, without shutdown or isolation of the asset under test, and presents requirements for compensation due to the inherent changes in steel velocity and attenuation with increasing temperature.
