Conditions for frangible roof

[caluna]

Hello,

Assistance please!

I know API 650 Section 3.2.10.6 specifies 6 conditions which must be met, including a limiting diameter of 50 ft.

However I do not have copy of API 937 which sounds as if it shows that tanks smaller than 50 ft dia may have franglible roof shell joints under certain circumstances. What are these circumstances?

I do not think the task we deal with here are anything special (are designed to anything other than 650) so assumed the ones less than 50 ft in dia were not frangible..

Thanks!!

 

[gr2vessels]

caluna,
The API 937-A edition 2005 (not the API 937 edition 1996) is indeed the standard dealing with the conditions under smaller API 650 tanks can be fitted with frangible roofs. Unfortunately, the standard has 78 pages and most of them are relevant to you, so I suggest to invest the cost of it in the project (eg. Chapter 7 is titled "Design Changes that Enable Small Tanks to Meet New Criteria";- it sounds attractive and promising, doesn't it?)
Cheers,
gr2vessels

 

[caluna]

Thank you very much! I guess we'd better spring for it. Sounds like riveting reading...

Caluna

 

[LeonEarle]

Gentlemen,

If you review the proposed Addenda 1 to API 650 11th Edition, available at the API website, you will find that instruction for frangible joints in tanks less than 50' is included. This addenda is not yet issued, but should be issued in the not to distant future.

 

[Daianto]

Thank you! But I cannot locate the Addenda 1 to 11th edition on Techstreet or API site. Could you give me a pointer as to where to find it?>

We did order and receive the 11th ed 650 (chapters are a lot different!-chapter 3 is now 5, etc) and also the 937-A 20o5 (which does explain necesary calcs to do the design for tanks smaller than 50 ft dia.) Bit I would like to get the Addenda 1 also.
Daianto

 

[Daianto]

Herad Addenda 1 (11th edition) is not out yet officially...

 

[JoeTank]

I hear it is still in "proof review"

Joe Tank

 

[JStephen]

See this page, which shows "Proof 2":

http://committees.api.org/standards/cre/scast/refdocs/docs.html

 

[Daianto]

Thanks very much!