Maintenance outages provide an opportunity to gain access to the tubes and other internals to assess their present condition, and to allow for data to be obtained to predict their the future reliability of the components. Inspections that can be performed during outages include:
a. Visual examination.
b. Wall thickness measurements.
c. Tube diameter or tube circumference measurements.
d. Tube sagging or bowing measurements.
e. Pit depth gauging.
f. Intelligent Pigs.
h. Hardness measurements.
i. Borescope/video probe.
j. In-situ metallography/replication.
k. Dye penetrant testing.
l. Magnetic particle testing.
m. Tube section removal for creep testing.
n. Tube section removal for metallography.
o. Tube removal for detailed visual examination.
p. Testing of tubeskin thermocouples.