Permutation tubes

The following discussion of wastage profiles is a result of observations made during many years of inspection. The classifications have been kept relatively broad as many permutations of these basic classes have been observed. It is also nor uncommon for two types of wastage profile to be evident on the same tube. 

This wide range of applications has resulted in an almost innumerable number of design permutations. These designs are normally based on multitube configurations but also include single-tube coil boilers. 

There are various types of cooling water heat exchangers to be found in use today, and the permutations of these may number almost as many as the applications in which they are employed. Jackets on chemical reaction vessels are a specific type of heat exchanger, as are the coil bundles in evaporative condensers, plate and frame and shell and tube heat exchangers. 

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