Infrared thermography for high-temperature pressure pipe

High-temperature pressure pipelines are extensively used in petrochemical plant and power stations. Severe pits or wall loss defects can be internally produced after a certain period of time due to media corrosion and cavitation erosion. These defects finally lead to leakage of the pipes. In order to search for a good non-destructive method for these defects, a large pipe testing installation was constructed. A series of infrared thermography testing experiments were performed for four kinds of stainless steel and carbon steel pipes which are drilled with different size holes on their inner-surface. The testing results show that infrared thermography is a very suitable method for non-destructive testing of corrosion pits and wall loss defects in high-temperature pressure pipes. The corrosion pits or wall loss defects that are bigger than 10 mm diameter x 40% wall thickness can be detected by infrared thermography. The testing sensitivity satisfies the requirements for safe operation of pipelines.