API-650 Addendum 4

When API issued Addendum 4 to the API-650 Storage Tank specification many aspects of the code were affected. The wind and seismic designs were change to try to bring them more into line with ASCE7, a new section for vacuum design was added, and a new section specifying load criteria was added. Sometimes the changes are difficult to interpret and time consuming to perform.

ITSdesign is a software program developed by Innovative Tank Solutions, LLC, to address these problems and to assist designers in meeting the requirements of the Addendum 4 of API-650. We are continuing to develop this program to meet the requirements of the code and the needs of the users of this design software.

Our goal is to help our users better understand what the code is requiring and how ITSdesign helps them meet those requirements. We want our users to better understand how to work with ITSdesign. To this end we are going to be posting questions and answers about both the API-650 code and the ITSdesign software.

We are working on adding AWWA D100-05 designs to ITSdesign and will be keeping you posted as to the progress on that part of the software. We will also be dealing with questions concerning this design code as there have been many changes to it as well.