API Inquiries

In the past one of the items at the API committee meetings has been the review of inquiries sent in by those of you who had questions concerning some aspect of the API-650, API-653, or API-620 codes. There have been some changes going on that has prevented this from happening or has reduced which inquiries would be reviewed at the committee meeting. After the last meeting I thought this had been worked out so that at this meeting inquiries would once again be considered. In fact the schedule has a time set aside for this. I had submitted several inquires last time and resubmitted them this time anticipating that I would have answers at this meeting. After requesting verification that my inquiries had been received by the right person, I received a reply that said API has changed their requirements once again on how inquiries are to be handled. I am not sure what all this entails but hope to have it explained at the meeting in November. What I do know is that some of the committees accepted this new process and are following it. However, the committee that would be reviewing the inquiries I submitted decided that instead of using the new process they simple would not review or answer inquiries. I do not now where this leaves us. We shall see.

Update on Addendum 1

I have been trying to find out when API-650 11th Edition Addendum 1 was going to be released. I finally got an answer back. They now say it will be released in "November or December". The way it has been going I would say it will be December. It appears that they are trying to clean up some of the typo errors that exist as well as adding the changes. I think they had a lot more of the committee checking over what they were putting into the addendum. In the process they made a lot of corrections which meant it had to go back to the editors and be revised and rechecked. Hopefully there will be very few errors they will need to be corrected after it is released. As far as Addendum 2, they have not indicated any date. Just that it will be next year. We may have a better idea when we get to the API meeting in a few weeks. I will keep you posted.

API-650 11th Edition Addendum 1

It has been a while since I posted. I will be trying to correct this in the future. First, there have been many questions concerning when Addendum 1 to the 11th Edition will be released. We are all still asking that question. I have asked API and am waiting for a reply. It might be November but we shall see. At the April meeting we were told that Addendum 2 would be released by the end of this year. Who knows, maybe Addendum 2 will be released before Addendum 1! I will be attending the API committee meetings in early November. By then we should have some type of answer.

I have submitted a series of inquires to API to try to get answered at this next meeting in November. After the meeting I will let you know what the results are of these inquires.

With regard to our software, ITSdesign, we have made several revisions to the program. An addition was made to allow you to enter additional wind moments and wind shears. We have added IPE, IPN, and HEA beam shapes to our SI database. We have also corrected some beam weight problems in the SI database. With regard to seismic designs, we have added a checkbox for entering "Peak Ground Acceleration" and values for "Q" to accomodate seismic areas not covered by ASCE7. Other minor corrections have also been done.

In my next post I will comment on some more of the changes that supposedly are coming in Addendum 1.

ITSdesign Additions

We have just released an update to our ITSdesign API-650 and AWWA D-100 tank design software. In this release we have added the ability to specify a maximum allowable stress for shell plates that is less than what is specified by the code. We also added a link to the USGS website for obtaining the seismic values needed. The biggest addition is that we added the ability to use channels and wide flanges as center and intermediate columns. The column can be either a single beam or it can be a composite beam. Drop down menus allow you to select which beam sections you want to use. Corrosion allowances can also be applied to the beam sections. In addition we have corrected a couple of printing errors. We are constantly working to add to and make corrections to our software.

New Revisions to ITSdesign

I have just posted a revision to ITSdesign. In this revision I added new data entries for shell and roof appurtenance weights in the corroded condition. This allows you to have a different weight for the new and corroded condition. I also added a new data entry for the percentage of the roof appurtenances that is transferred to the shell. For column supported roofs this allows you to specify how much of the weight is transferred to the shell for resistance to overturning. The appurtenace weights have also been added to the resistance to uplift when internal pressure is present. For wind girder required section modulus I have added the 'm' factor to account for increased loading per 5.9.7.1. I also added to check whether Appendix F calculations need to performed based on the weight of the roof and appurtenances as compared to the uplift due to internal pressure.

For those who are using ITSdesign, see the Revision block for other minor revisions to ITSdesign. We continue to strive to make ITSdesign as accurate and complete as possible. Suggestions for additions and corrections are always welcome.

API-650 Appendix J Material

I have been debating about what to do with the material requirements for an Appendix J tank. What is specified in J.2 is that the material must meet the requirements of Section 4. This would mean that if you use A36 material in a shop built tank with a design metal temperature of -10 degrees F, you would have to impact test the material. What is strange to me is that if I built that same tank to Appendix A the material does not have to be impact tested per A.2. I plan on presenting the question to the API committee at the next meeting. In the meantime, I have added a checkbox to the design page of our software where you can select to use the material limitations of Appendix A. Each user will have to determine whether their customer will allow them to use the material as specified in Appendix A instead of the requirements of Section 4.

We have made some additional modifications and corrections to ITSdesign. Be sure to read the revision notes to see what we have done.

API-650, 11th Edition, Addendum 1

I am continuing to review Addendum 1 to the 11th Edition of API-650. Here are some comments on what I have found so far.

1) There are many slight modifications in the values used for SI units. Places that used to specify 12.5 mm now use 13 mm. In the table for 5.1.5.9(e), they have revised the angle size slightly. In 5.5.1 they changed 172 MPa to be 171 MPa. In 5.6.3.1 they changed the limit for using the 1-foot method for shell design to 61 m. Revised the angle size in 5.9.3.1 and 5.9.3.2.
2) In 5.2.1 (loadings) they revised the external pressures so that tanks with internal floating roofs with circulation vents do not require a minimum external pressure.
3) In 5.2.1 they also added loading requirements for internal floating roofs.
4) In 5.6.1.3 they added additional rules when using a lower allowable stress material in the upper courses. You now can do an elastic analysis or the lower course must be no thinner than the required thickness for product design or hydrotest design of the upper course.
5) They have revised some of the tables for manway neck thicknesses, nozzle reinforcement, cover plate thicknesses, and flush cleanouts.
6) For intermediate wind girders, the shell course thickness is now to be based on the thinnest shell course which may not be the top shell course.
7) An expanded design for frangible roofs has been added.
8) 5.10.2.9 now states that the purchaser can specify that lateral loads be imposed on the roof supporting columns.
9) 5.10.3.2 has been revised to reduce the minimum thickness for roof support columns from 0.25" to 0.236".
10) 5.10.4.4 has been revised to provide calculations for the maximum spacing of the roof rafters. It also set the maximum spacing at 84". These limits apply to both inner and outer rafters.
11) 5.11.2 has been revised to add a limit on the value of wL for the wind condition. It also now specifies that tb is in the corroded condition. A calculation of the minimum annular ring width for wind has been added.

This covers most of the changes I see in the design section (Section 5). Next time I will give you information on the changes to the various appendices and which new appendices have been added.

To keep our software, ITSdesign, current, we are already working on the revisions to incorporated these changes into ITSdesign.