Detection of corrosion of carbon steel tubes at and within the tube sheet in a shell exchanger

Practical NDT on site often involves finding an acceptable technique rather than aiming for perfection. The constraints may be accessibility, the general condition of the unit, restrictions imposed by the technique (for example radiation hazards from X or gamma sources) or the time available. Innovation and adaptation sometimes provide an answer where conventional approaches fail. Here, a magnetic-based technique solved an urgent problem in a shell exchanger.