Code enforcement future 2

[pveng6224]

This may sound off-the-wall, but I have it on good authority that Sec VIII Division 1 will become less common and Division 2 will become more standard over the next few years.
Can anyone point me where to look into this further or does anybody else have any facts on this themselves ?

Thanks

pveng6224

 

[metengr]

This may sound off-the-wall, but I have it on good authority that Sec VIII Division 1 will become less common and Division 2 will become more standard over the next few years.

It is an off the wall statement.

 

[Ganfoss2]

Much probably you are right, but I think that the future shall be EN 13445 vs. ASME VIII/2 (now ASME if the favorite one: more diffused and still more "easy to apply" even if now is more close to EN!).
NOTE: do not forget that Codes also prescribes requirements also at the Manufacturing stage and also on Materials and on Non Destructive Examinations stated in the Quality Production Plan that have an impact on costs and on the delivery time of an Equipment.
My personal feeling is that EU and EXTRA-EU Engineering Companies and Final Users of Pressure Vessels wish to use a Code that is ... "extremely easy, clear and simple to use/apply, without spending too much time on the interpretations of its Requirements (where the rule is not so clear or lead to multiple interpretations). Further more if it would be possible to turn the Codes as a list/collection of "Rules of the Thumbs" without too much formulas and no "complex" design procedures (trial-and-error recursive & non linear design procedures) ... it would be fantastic!"
This to reduce the time spent during the design activities (huge number of vessel to design & fabricate or to quote in short time) and to reduce the costs of the Personnel employed in the Department appointed to “follow” Pressure Vessels (during engineering or during their life in the production plant).
NOTE: I hard in the past some NOT POSITIVE comments on the new issue of ASME VIII-2 (i.e.: too complex to use, to difficult to read, no software available in short time). The “SOFTWARE FACTOR “ play a significant role in the diffusion of a Code!
Personally I prefer EN 13445 (even if it is permanently under review and often use "very complex" design procedures – German style!) and I prefer ASME VIII-2 respect to ASME VIII-1 since now it is easier to understand the "design philosophy" that stays back on the Code Requirements.
Furthermore EN-13445 and ASME VIII-2 are now two MODERN DESIGN Codes that implement the current develop on the Technique of Design (that require a more skilled user, possible a graduate technician) on the Materials and on the NDE/WELDING Technologies.
Who shall win among ASME VIII-2/EN-13445 and ASMEVIII-1 depend on who shall govern the market of Pressure Vessel Manufacturing and Engineering (USA/EU or FAR AND MIDDLE EAST - now the second is is the most favorite one!)

 

[PVinspector]

It has been mentioned by people on the ASME Code committees who work for Hartford Steam Boiler, that Section VIII-1 will likely become a bit more like VIII-2, maybe not in the next several years. The Code moves slowly.

This would mean more emphasis on UG-22 loadings, and ultimately a Users Design Specification similar to what Division 2 requires. Maybe even more flexibility on design margins with NDE, but that is uncertain at best.

There are a lot of powerful interests who make very simple VIII-1 vessels that will fight any additional design responsibilty vigorously, so I don't expect big changes in the near future at all.

 

[jte]

The basic argument seems to be “If the Div. 2 rewrite is good, why not adopt it with suitable modifications as a new Div. 1?” The modifications would involve things like the design margin and NDE. I don’t see this happening within 5 years. Maybe 10.

The concept of a User’s Design Spec for Div. 1 is also being seriously discussed – I see this happening in the “near” future. As long as one defines “near” as 5 years or so. But it could be less, maybe 2 years. This is a separate issue from a complete rewrite.

In any case, I see the proportion of vessels being built to Div. 2 increasing, maybe even doubling to 2 or 3% (no, I have no basis for that percentage). But the vast majority of Section VIII vessels will continue to be Div. 1 for a long time.

jt

 

[gr2vessels]

A small contribution to the discussion, just in case has anyone missed the summary (attached);-

Cheers,
gr2vessels

 

[Crompto29]

Div 2 is for 'Alternative Rules' and I would expect it to stay that way.

ASME VIII-1 seems basic and easy to apply using hand calcs. Whereas much of ASME VIII-2 involves advanced analysis.

I can see that as some Div 2 'alternative' rules catch on they will be absorbed into Div 1. However for engineers that don't have the relevant Div 2 FEA experience, Div 1 may become a bit complex. Especially as there are non educated engineers designing to Div 1.

EN 13445 has a way to go before it is simple enough to be in common use.

I've been designing vessels to the simpler PD 5500 for different countries in Europe. The EU standard is supposed to be eclipsing it? I haven't used EN 13445 yet.

Is it in common use by anyone out there?

 

[LordOfSnow]

Crompto29,
The EN13445 is in common use in Europe. It is maybe most used in the countries that have contributed less to the standard, like Finland, Norway, Sweden, and Eastern Europe.

The major contributes to the standard development have been UK, France and Germany, with their national standards (like PD5500 for Uk as you mention).

In my opinion a great standard, that covers most aspects of a pressure vessel, external loads, a competitive flange calculation... But to take any advantage of the more advanced methods presented, you will need a good PV software. (At least if you plan to have your vessel ready for manufacture before you retire.) My opinion only..

 

[Crompto29]

Cheers LordOfSnow,

Maybe I should have said, I will need allot more enthusiasm before attempting to design a chamber by hand or spreadsheet with EN 13445.

e.g. The pressure area method may be more competitive with ASME but without software it will take forever to design. Is saving a few square millimetres of reinforcement for a one off vessel in a small engineering firm actually more competitive?

My small firm is keeping it simple with PD 5500 with our one off vessels. I'm dreading being required to design to the EU standard if it is specified. That is a lot of spreadsheet work.

How do other people train there young engineers? How do firms train their engineers? Just show them how to use PVElite and nozzle pro and hey you’re a pressure vessel design engineer? Of course pressure vessel design is more then just code rules.

 

[gr2vessels]

The PV Elite and Nozzle Pro calculations per ASME/TEMA codes are almost exclusively prescriptive design tools, not much engineering is required, apart of reciting the code backwards. In the last few years, perhaps some room was given by the ASME code, but basically not much change. Also, very few back-up engineers to take up the trade...
Cheers,
gr2vessels

 

[roca]

the problem with software and young inexperienced engineers is the general equation:
= rubbish in = rubbish out.
Like Crompto29 says its not just about typing on a keyboard.....

 

[roca]

example to go with my last post (can't remember the exact dimensions involved):
A few years ago a young graduate was doing a vacuum design on a vessel.

He punched in all the numbers and hey presto the computer accepted his design.

He had used a stiffening ring that was someting like a 100mm x 100mm square section. It worked so must be correct.

However as we all know this section would not be used on a vessel.

We all have to learn and experience (IMO) counts far more than being able to zoom your way around some software.

 

[DSB123]

roca,
Unfortunately that's the way the world/engineering is going - loads of inexperienced "engineers" banging numbers into computer software. I tend to blame the software developers making the software too easy for "numpties" to use. As you say GIGO is very prevalent. An exam[ple is the number of third world countries that have engineering "design houses" just ready to bang numbers into software and get "designs" out which in-evitably have to be done several times before an acceptable solution is reached. This will only reverse when there is a large number of incidents.

 

[LordOfSnow]

In my opinion, the use of software for pressure vessel calculations is not about your level of experience. Shit in = shit out, wether you use homemade spreadsheets, code software (advanced spreadsheets) or FEA (very user dependent).

However, by applying a recognized and up to date software for your vessel calculations, you:
- Ensure that your calculations are in accordance to latest code edition.
- Gives your 3rd party inspector (as required by PED for certain vessels, and also often for offshore and ship vessels) a easy job, as he will only need to evaluate if your input make sence, and not if you have an error in your calculations.
- Save time - use it on design rather than calculations.
- Quite easy to try different designs and to get an optimized design of your vessel / check if the prefered solution from a manufacturing view is ok, or if you need to adjust to meet code requirements.
- And many more.

What the software will not contribute with, is the engineering part of of the job - what loads you apply (nozzleloads, wind, earthquake, blast pressure, cyclic loads/fatigue..), the evaluation of the practical aspects and of the results you calculate. As well as specifying proper weld details, NDT test plans etc.

The combination of an experienced engineer with a good software for calcs and close contact with the workshop to evaluate the manufacturing aspects of the product - great!

 

[gr2vessels]

I like the saying rubbish in = rubbish out. However, it takes an engineer to devise the machine to extract some good out of the rubbish...
Cheers,
gr2vessels