Need examples of welded products that maintain airtight/hermetic seal for 15+ years

[Anders74]

Hi everyone,

I'm looking for some proof that thin stainless steel (8-15mils) can be welded to contain a vacuum seal for 15+ years with minimal pressure change. Some products I found are vacuum insulated panels, vacuum insulated pipes, vacuum insulated food containers, and hermetically sealed electronics packaging. Any tips would be greatly appreciated!

 

[racookpe1978]

The "longest stored" (although in a clean area with nitrogen pressure applied to eliminate moisture and contaminants) very thin pressure vessels I'm aware are the 30 thousand thick NASA moon rocket RP, LOX and LH2 fuel tanks and stages and their engines. Built 65-66-67-68 time period, kept until launch in the mid-70's.

 

[racookpe1978]

Now, if you have NASA's 1960's budgets ....

 

[itsmoked]

Stainless thermoses.

Billions of aerosol cans.

Keith Cress
kcress -

http://www.flaminsystems.com

 

[IRstuff]

Not sure about the lifetimes, but there are millions of vacuum Dewars for military infrared detectors that probably are good for at least 10 years. They're typically soldered for the detector window, pumped down, and then the copper vacuum nipple is pinched off.

TTFN (ta ta for now)
I can do absolutely anything. I'm an expert!

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[Anders74]

Thanks, folks! In case anyone is interested, I turned up a few others: welded metal bellows (leak rates < 1e-9), cryogenic dewars storage containers for liquid nitrogen, and lots of medical products in general.

 

[itsmoked]

That's right! Lots and lots of pressure gauges have those Bourdon tubes though a lot might be brass and soldered rather than steel and welded.

Keith Cress
kcress -

http://www.flaminsystems.com