NDE Techniques for Reliable Inspection of Carbon Steel Tubes

Ferromagnetic tubes in Heat Exchangers, Boilers, Air Fin Coolers are most common in the Petrochemical Industry. Carbon Steel, an inexpensive material has good mechanical properties and heat transfer capabilities. However, it is often employed in conditions where corrosion if it sets in, acts very fast. Over the years with shrinking maintenance budgets and longer intervals between plant shutdowns the need for reliable inspection of these units has increased. The advent of digital technology, several enhancements to the inspection equipment based on RFEC, Magnetic Flux Leakage, Ultrasonic IRIS have taken place. Each of these techniques has its own merits and demerits. This paper presents an overview of the techniques available for carbon steel inspection discussing their merits and demerits.. It also presents a methodology of selecting the right combination of techniques to achieve reliable inspection results using practical case studies of field work carried out.