Significant Technical Changes Made to API 653

By Vince Carucci

Significant technical changes are included in Addendum 3 of API 653. Many of these changes relax requirements that were included in prior editions of API 653, and compensate for this by increasing inspection and/or engineering review requirements. Other changes provide additional clarification for what is required by this standard.

The following summarizes several of the significant technical changes that were made. See Addendum 3 for complete details.

See Addendum 3 for additional requirements and limitations.

The changes to API 653 made in Addendum 3 are, in many cases, welcome relaxations of previous requirements that were unnecessarily conservative. They also more clearly permit experienced engineers to use their judgement, knowledge, and alternative methodologies to evaluate storage tank integrity. Companies with established storage tank inspection, maintenance, and repair programs should review them in light of these revised API 653 requirements.