AQUASTORE Tank Service Life Bulletin

When conducting a life cycle cost (LCC) analysis for a storage tank, estimating the life expectancy of the tank is very important. Life expectancy affects the period of evaluation, salvage value and ultimately the total life cycle cost. There are several different ways of reliably estimating tank life. A recent article by Mr. Bill Neighbors in the July 2010 Water and Wastes Digest titled “Specify Wisely” is one method, purely the opinion of one supplier, that appears to lack substantiated third-party accreditation.

The table below (Figure 1) from the “Specify Wisely” article describes a concept called PDT (Plate Design Thickness) to estimate tank life, but does not detail how PDT is calculated and does not reference any third-party independent source that recognizes the PDT methodology. The table implies that several noteworthy standards organizations estimate tank life using PDT. These organizations do not reference this PDT methodology in the standards noted in the table.