ASME Pressure tank as a vacuum receivers?

[Joseph_L]

I am looking for a vacuum receiver tanks, and I could not find many.

I read some online forums about ASME pressure tank code, and they do talk about external pressure stability. Can I use an ASME pressure tank as a vacuum receiver tank?

The tank is subject to go through cyclic load of vacuuming and partial purging probably 5 times a minute.

Thank you in advance

 

[SnTMan]

Joseph_L, one more thing about your analysis, if it has been mentioned I didn't see it.

No openings? Any pressure vessel without openings is....useless.

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[LittleInch]

I was being a little harsh there, but the point remains. Clearly vacuum receivers have very different load and stress paths than positive pressure vessels and especially for the lower rated receivers like air receivers, they just are not suitable for use as vacuum receivers.

So if it costs 4-6 times then that's what it costs for something that will last for years.

Try a non certified design intended for a different purpose and see what happens, but if it fails in service this will be a false economy. But will you be long gone by then? Or will the plant manager remember you saved a couple of thousand dollars in construction, but now the plant is down for 5 days while you fix it which results in hundreds of thousands of dollars lost revenue?

Your choice.

But please let us know which choice you made and why.

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[Joseph_L]

@SnTMan, There will be openings... I did not worry too much about the openings at this point, as there will be a port (NPT, Tri-clamp, etc) which would enforce it.

@goutam_freelance, I followed section VIII - Div 1. Got Factor A and B, and from that, I calculated Pa (allowable working pressure).
Yet, I don't quite understand the result. What is the unit of Pa?
If I have not made any mistakes, I got Pa = 0.25 when 1/8" wall is used for 20" dia. (L = 42.5")

@LittleInch, I understood. I know the obvious answer from the engineering standpoint.
The challenge is, the person who will approve or reject my proposal is not an engineer.
I will have to fight against many scientific mythe, company's financial related issues (upfront cost vs. future hidden cost, etc), and many rather interesting 'educated guess' from another field of engineers.
I can easily expect a situation where many conceptual thoughts are thrown at me, and in many cases, those concepts are outside of my comfort zone.
I was trying to think of many other solutions/approaches (nickel and dime basically) to prepare myself in that situation, which would bring you to the uncomfort zone.
But I do appreciate your pushback on me for going non-standard routine.

 

[Joseph_L]

In case anyone is experiencing the same problem,
Factor B has a unit of MPa. (Strangely the chart that I was referring to is missing a unit).
Pa = 0.25 [MPa]. -> 36 psi

 

[SnTMan]

Joseph_L, I ran a guesstimate calculation based on your previous posts, assuming CS material at up to 300 F. I got 33 psig. Mind you, this was for the cylinder only. Calculations shall be made for each component of the vessel, including perhaps opening reinforcement. Lowest value wins.

There is still the cyclic service aspect. That will likely not be so easily finessed.

The problem with sloppy work is that the supply FAR EXCEEDS the demand

 

[AzriHms]

Yes you can use a pressure tank provided it MUST be protected by means of having Vacuum Safety Valve or Breather Valve.

 

[LittleInch]

Azrihms.

Did you read the post?

The OP wants to use a standard positive pressure vessel as a vacuum tank. So having a vacuum valve or breather valve means it won't work!

Remember - More details = better answers
Also: If you get a response it's polite to respond to it.

 

[goutam_freelance]

The stress seems to be well under its fatigue strength.

Yes, assuming carbon steel material Ultimate strength S_ut=60 ksi=414 MPa. The nominal endurance strength S'_e=0.5S_ut=207 MPa. Assuming various fatigue strength modification factors as 0.6 (guess) the fatigue strength S_e=0.6S'_e=124 Mpa.
From your FEA output the max stress is 24 MPa. So it appears safe in fatigue. But this needs to be worked out in detail including the effects of openings where stress can concentrate.


Engineers, think what we have done to the environment !

https://www.linkedin.com/in/goutam-das-59743b30/

 

[FacEngrPE]

Designing for external pressure is more complicated than for internal pressure. The failure mode on exceeding the vacuum limit is sudden buckling collapse.

https://www.pveng.com/home/asme-code-design/external-pressure-methods/