API-650 11th Edition Addendum 1

It is now released! We have just released the revisions to ITSdesign to bring it into conformance with API-650 11th Edition Addendum 1. We have added a button so you can select whether you wish to use the 11th Edition or whether you wish to include Addendum 1. For Addendum 1 we have made changes to the Appendix F calculations as it now requires the use of yield strength of the material in the calculations. There are also changes to Appendix E to take care of adding a internal pressure factor in the calculation of J and changes in the calculation of annular rings. From the base code we have revised the check for maximum spacing of both inner and outer rafters, revised the check for minimum thicknesses in many places, and revised wind calculations. We have also added the requirements for duplex stainless per Appendix X. We will continue to add functions the ITSdesign program and will keep in conformance with the latest addendums.