ASME versus A97075

[Progger4]

My first post ever - though I've been lurking around for quite a while - and it is a question.

Why isn't wrought aluminum 7075 (A97075) and any of its tempers listed on the ASME stress tables?

I need a small pressure vessel to withstand 6500psi at 40ºC. The vessel will act as a sample holder in a tomograph, so the vessel material has to be aluminum in order to not interfere with the analysis.

The mechanical engineers say they can not design the vessel using Al7075 simply because this alloy is not listed on the ASME stress tables, hence my question.

Thank you.

 

[AIOR]

The starting point for a material selection would be a construction code such as ASME Section VIII Div. 1. Your material UNS A97075 is not listed in Div. 1, and also not listed in Div. 2. You can not use this material in Code pressure vessels.
You can build small pressure vessel as a non-code vessel if it is acceptable to the jurisdictional authority who enforce the pressure vessel law at the place of installation. It is possible because per ASME Sect. VIII Div. 1, see U-1(quote) “vessels having an inside diameter, width, height, or cross section diagonal not exceeding 6 in. (152 mm), with no limitation on length of vessel or pressure are not included in the scope" of the Code.

 

[4Pipes]

In additions to AIOR's useful suggestion, given the small size, could it be an option to make a ASME code vessel with a lower strength aluminium liner? I would suspect that the liner would form a tight fit after pressure testing.

 

[Progger4]

Thank you AIOR and 4Pipes for your help.

The vessel has to be integral, so the lining suggestion is not an option.

However, my question remains. Is there a reason why this alloy is not listed in either Div 1 or 2?

 

[vesselfab]

one would have to assume that there is one or two reasons.

1> No one has requested this material yet

2> The committee that oversees the material selections, feels that it is not material suitable for pressure vessel.


Have you made request to the code yet?