Hermetic Seal

[design-engine]

How would you show a hermetic seal or welded seams on a sheetmetal part?


http://en.wikipedia.org/wiki/Hermetic_seal

 

[wsylvester]

I would think that would have to be stated in a note and to what level the seal is.


There is a gross leak check and a fine leak check.


Gross leak the part is set in a heated fluid <forget what it's called> and you look for bubbles.


While fine leak the part is generally placed in a pressurized tank where helium is used for "x" number of hours then the helium or part is removed and then placed in a vessel that has a helium sniffer... size dependent


they use helium as it is one of the smallest atom, if not the smallestand able to get through most materials.


At least that's what the requiremnts were for military space componets

 

[design-engine]

William,

You got me really thinking. Thanks.

 

[ankarl]

You can use air to do a fine check as well (even though nothin beats Helium).


Pressurise and measure the leak with a device. Takes about 5 minutes in a complex part (need to fill all voids before measuring). We're using equipment called "Nolek" or "Nolec"

 

[sonics]

I think what the question was how can you show a weld on a sheet metal part to create a hermetic seal at the seams. All you have to do is create an assembly for the part, constrain it to the default, then start the welding application and create your welds on the seams. Once that is done now you will have your weld symbols established for your detail drawing. I would just add a note that the part must be sealed to what-ever spec. needed.

Sonics

 

[puppet]

Hey Bart,


Love to know what your working on bart. Not many people i know of work on hermetic projects, and the ones that do generally dont know it themselves!

 

[design-engine]

always top secret.this one will fly at very high altitudes. where you been puppet?

 

[puppet]

Hey Bart,


New job, only cad work i do now is overview layouts Still pop in every now and again to see whats new Actually thinking of contracting my self out for some easy legacy conversions, but its just a thought. USD -> AUD conversion works well for an empolyer in the usa side HInt HInt


Been well mate? Still helping people over construct surfaces to patch a 5 sided hole?


Hows life in the USA treating you with the financial stuff thats happening?

 

[design-engine]

Companies (and upper management) likes to slash budgets for training first. They do so by cutting the travel budget.... so we get webex... then they cut the budget for training itself.Bad Idea if you ask me. I think the managers (after laying so many contractors and perms off) should invest in training so they can get the job done faster and with less people. I read the book 'death march' and I am always up for the impossible projects.

Lots of new stuff happening... I use my holiday usually to learn something new... not sure what it will be this year.... I am thinking of making training videos for Pro/CABLE and RSD and offer them online.