New techniques for monitoring the cause of operational damage and determination of actual damage to heat exchangers

Details are given for the use of the Acoustic Pulse technique to determine the condition of heat exchanger tubes. Using the technique, extensive damage was found in one section of a Feedwater Heater. Vibratory sensors were placed on the shell of the heater and continuously monitored. From this data, the cause of the damage was established, and the specific times during the normal operating cycle when such damage occurred was identified. Spectral data was then taken at frequent intervals, from which further degradation of the heater was deduced. As a by-produce of the spectral data, it appears that this method can detect the onset of the cracks in the shell expansion joint of such heaters, long before the effects of such cracks are able to be detected by means previously used