Contact US

Log In

Come Join Us!

Are you an
Engineering professional?
Join Eng-Tips Forums!
  • Talk With Other Members
  • Be Notified Of Responses
    To Your Posts
  • Keyword Search
  • One-Click Access To Your
    Favorite Forums
  • Automated Signatures
    On Your Posts
  • Best Of All, It's Free!

*Eng-Tips's functionality depends on members receiving e-mail. By joining you are opting in to receive e-mail.

Posting Guidelines

Promoting, selling, recruiting, coursework and thesis posting is forbidden.

Students Click Here

application of pressure vessel in vacuum service

application of pressure vessel in vacuum service

application of pressure vessel in vacuum service

hello every body
In the oil and gas company there is a pressure vessel with name plate that shows the specification as follow:
design pressure (MAWP): 10 barg
design temperature: 100 C
length: 8 meter
I.D = 2.5 meter
material; carbon steel
and there is not any information about vacuum design pressure.

we want to apply this pressure vessel in another system that all conditions (pressure,temp., flow rate ,...) are same as above but there is possibility of vacuum in some scenario.

Can we use this pressure vessel for new service?
in the other hand can we say that " because of this pressure vessel is suitable and resist for 10 barg then it is suitable for vacuum services".

thanks for any respond.

RE: application of pressure vessel in vacuum service

Clearly the answer is NO. You need to provide a code calculation by considering the diameter, wall thicknesses, and circumferential stiffeners if it has any. By looking at the diameter only I would say it will not take full vacuum at all.

RE: application of pressure vessel in vacuum service

You need to have your vessel certified for vacuum .


RE: application of pressure vessel in vacuum service

I also agree. Vacuum service is very different to positive pressure.

You cannot assume that just because the vessel is good for 10 barg it is good for -1 barg.

It might be but you need to do the design work and recertification is required.

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

RE: application of pressure vessel in vacuum service

I agree with the three comments above ....

Additionally, if the pressure vessel were to be "re-used" here in the US, there is an issue of re-certification by the National Board.

Here in the US, if you have an ASME pressure vessel and operate the vessel outside of the limits of design, then you must re-certify via the addition of an "NB" stamp. This is done by paying for a rerating by an organization qualified by the National Board


We, of course, do not know where in the world that you are located .... I can only guess

Sr. Process Engineer

RE: application of pressure vessel in vacuum service

thank you every body .
based on your comments, I understood the vacuum vessels has own calculations.
Just to better understanding the subject (me), imagine the design pressure was 100 barg instead of 10 barg (we don't have this vessel and just imagine if we had) , what was your answer in this case?
your answer is vessel should be certified for vacuum even for 100 barg?
I try to understand which parameter of the pressure vessel is more important than another when we encounter with vacuum systems? length or diameter or thickness or ...?

RE: application of pressure vessel in vacuum service

Don't believe that it was stated anywhere that this is a code stamped vessel. It looks like you are located outside the United States and you will have the follow whatever code is in place in your country or on your particular project.

You need to do the calculations to determine if the vessel will withstand vacuum. You also need to determine the age and condition of the vessel.

It is not uncommon for smaller diameter vessel to be capable of withstanding vacuum if the design pressures are elevated. For larger vessels, the steel is generally to thin.

RE: application of pressure vessel in vacuum service


The answers provided would not change based on the MAWP, be it 10 or 100 bar. As the MAWP increases, the greater the likelihood is that the vessel will have a full vacuum capability due to increasing metal thicknesses everywhere to hold the higher MAWP. However, without proper design calculations, it is impossible to know if the vessel would be able to withstand a full vacuum.

RE: application of pressure vessel in vacuum service

Let's be realistic here. 10 bar design on a 2.5m diam PV is going to be fairly decent. 100 bar even more so.

So the chance that the PV will fail a design check for vacuum with a MAWP of 10 bar is probably 10 to 15%
With a MAWP of 100 bar reduces to probably 3-5%.

But it is not ZERO chance.
And it won't be certified if you just do it anyway and then the vessel collapses or becomes damaged in some way.

There's no one parameter more important than the other. They all interact with each other

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

RE: application of pressure vessel in vacuum service


Having gone through a PV design process for a 10' diameter vessel a few years ago, I can say that had we increased MAWP from 50 to 100 psig and increased head thickness by one size (from 3/8 to 1/2", if I remember correctly), the vessel would have passed calculations for F.V. without any stiffening rings. From this, I agree with your % assessment on holding vacuum, and that this vessel is more likely than not to pass checks for vacuum.

However, in many places in the world anyone can put a stamp with a MAWP value on anything without oversight. OP didn't state the design code or certification authority for that stamp, so there isn't any telling if our normal assumptions are correct.

RE: application of pressure vessel in vacuum service

My guess is it may be ok for FV. But a guess is not good enough. In many countries, the plant owner may be prosecuted for operating a pressure vessel beyond its design limits. So you should get a professional registered pressure vessel design engineer to document the calcs for FV operation and have the calcs peer reviewed also. The mechanical static technical authority in this plant should then check and sign off authorisation to extend these operating limits. Then the plant owner representative should write out an application to your national pressure vessel board to get the registration info for this PV amended, with these supporting calcs and conclusions.
If the source of this new requirement is from plant process operators, a process safety audit should also be conducted to formalise this request and address any other attendant concerns.

RE: application of pressure vessel in vacuum service

Quote (142846)

Can we use this pressure vessel for new service?
It is a widespread practice to put a mid pressure vessel in vacuum service and find out that external pressure requires much more thickness of metal. You are not alone.

Each loss prevention book contains fotos and descriptions of cases this kind of. For example see:
- Kletz's What Went Wrong
- Sanders' Chemical Process Safety

Also there is a lot of videos how such pressure vessels collapse:

Red Flag This Post

Please let us know here why this post is inappropriate. Reasons such as off-topic, duplicates, flames, illegal, vulgar, or students posting their homework.

Red Flag Submitted

Thank you for helping keep Eng-Tips Forums free from inappropriate posts.
The Eng-Tips staff will check this out and take appropriate action.

Reply To This Thread

Posting in the Eng-Tips forums is a member-only feature.

Click Here to join Eng-Tips and talk with other members! Already a Member? Login


Low-Volume Rapid Injection Molding With 3D Printed Molds
Learn methods and guidelines for using stereolithography (SLA) 3D printed molds in the injection molding process to lower costs and lead time. Discover how this hybrid manufacturing process enables on-demand mold fabrication to quickly produce small batches of thermoplastic parts. Download Now
Design for Additive Manufacturing (DfAM)
Examine how the principles of DfAM upend many of the long-standing rules around manufacturability - allowing engineers and designers to place a part’s function at the center of their design considerations. Download Now
Taking Control of Engineering Documents
This ebook covers tips for creating and managing workflows, security best practices and protection of intellectual property, Cloud vs. on-premise software solutions, CAD file management, compliance, and more. Download Now

Close Box

Join Eng-Tips® Today!

Join your peers on the Internet's largest technical engineering professional community.
It's easy to join and it's free.

Here's Why Members Love Eng-Tips Forums:

Register now while it's still free!

Already a member? Close this window and log in.

Join Us             Close