NDT AT HIGH TEMPERATURES 1

As for checking the the thickness of the vessel, it can be accomplished by using a Panametrics Model 36 Thickness Gauge with a D790 probe. The Probe has a range of approximately 480 deg. C. Be sure to use a high temperature couplant such as Sonotech 900. Verify the instrument calibration at that temperature by placing the calibration block on a manway flange if possible.

Crack propagation at that temperature is difficult. Due to personnel and equipment protection.

Thermal Imaging may be a useful NDT tool in this application. If the wall thickness has changes it should show slight variations in temperature. This is a good non-contact way to quickly evaluate the condition of a vessel. I recomend that the inspection be performed by a certified level 2 or 3 thermographer, with a modern imaging rediometer.