Vessel drafting: 2D vs. 3D 2

[bhuffman]

Hello, I work for a fabricator of ASME code vessels and heat exchangers. We have been using 2D autocad to detail vessels for years, but people (mostly salesmen) are telling us we could save drafting time by switching to a 3D package such as Solidworks or ACAD Inventor.

Does anybody else in this industry have experience with this switch? Is the hassle of the initial learning curve worth the long term time savings (if any?)

Also, has anybody had success with semi-automated 3D models, for example outputting a solid model from Compress, PVElite, or Aspen Teams directly to Solidworks or Inventor?

Any help or advice would be appreciated.

-Bill

 

[waskillywabbit]

I can just see the nightmare of trying to get the shop to read a 3D drawing (something new).

And when is the last time a salesman actually told you something that was true or something that would not make them a profit?

Brian

 

[PatBethea]

See thread724-174131

 

[3dwaytogo]

Hello, I have been working with 3D models for approx. 15 years, the reply from waskillywabbit just makes my blood boil, please allow me to give you some information, 3D does not give you 3D drawings to send to a fabricator, 3D models give you a 3D full scale parametric view within a software package, depending on the package, most will then let you take drawings from that model, sections, plans, isometrics with bill of materials if necessary, in plant design, you will have all clashing capabilites as well as a host of other functions, the applications are endless to the right company that wants to go that route, there is 3D software for equipment in particular, companies that do not use 3D over the course of the next 3 years (Daratech May-2008) will slowly get behind and not be able to bid/compete against other established 3D A&E firms.
thanks for letting me vent.
Rich

 

[DG72]

We use AutoCad at our company (we have customized it heavily). Some of our draftsman have good familiarity with Solidworks, as well as other packages. They do NOT feel that it would be a good fit for our company (we manufacture TEMA type heat exchangers).

 

[jistre]

Agreed with 3dwaytogo. I never worked in vessel/HXer design, but I did do product design in my last life and we exclusively used a solid modeling package. For lack of a better name, we'll call it "SomethingWorks". The time to model something in these packages is MASSIVELY reduced once you get everything set up and learn how to use them.

Also, these packages are going to generate standard 3 views and isometrics to whichever standard you wish (i.e. ANSI, ISO, JIS, etc.). I'm not exactly sure what a 3D drawing is, though. Also, if you're dealing with parts requiring NC work, you can often skip sending prints to the jobshop completely and just provide them a copy of the model file that their machines translate to a tool path if you so choose. But, other than special things like that, the prints these packages produce are standard engineering prints.

Where you see a real benefit for using some sort of solids package in designing things like S&T HXers would probably be in time to produce prints. Each exchanger requires its own prints specific to the exchanger, but on the whole, these exchangers are very similar in their geometries. These packages are pretty powerful and I'm fairly certain that you could set up a template model file with the basic geometrical relationships that go with each type of head, channel, etc. Then, you just parametrically set up a selection routine that allows you to tell it you want a flanged and dished head shell, 30" ID with a 5/8" wall thickness, 10 feet long, and provide it with a nozzle schedule and the program then uses your inputs to modify the model based on your pre-set rules and then uses previously created drawing templates and the information you provided to spit out prints ready for checking.

Granted, this is pretty advanced stuff, but it can be done.

 

[waskillywabbit]

3dwaytogo - Glad to know I have the power to make your blood boil. Your name shows your bias. Have you ever done any ASME pressure vessel/HX design? Ever fabricated one?

A&E firms are not fabricators. I work for an ASME fabricator and while 3D modeling is certainly beneficial when desiging a pressure vessel to check for possible interferences, 3D drafting is unneccessary as almost all pressure vessel/HX design programs already incorporate 3D modeling.

As far as detailing or drawing out the vessel/HX for fabrication, 2D AutoCAD is more than sufficient.

jistre - you readily admit you have done no vessel/HX design yet you want to talk about modeling a pressure vessel/HX? PV Elite and COMPRESS are two softwares I am familiar with and both model your pressure vessel/HX for you without having to use a 3D CAD program at all.

What works on paper or even the computer does not always work in the real world (fabrication).

Brian

 

[GoofyatEEE]

waskilly - While I will agree that 2D AutoCAD is more than sufficient there are some real benefits to going 3D. Automatic updating of all drawing sheets and BOMS upon model update is the biggest one.

At the ASME fabricator I worked at we made vessels that were of similar design with minor changes to either nozzle sizes, locations or both. I could call up an old model that was close, make the changes to the model and be confident that all the sheets and the BOMS were updated.

The other advantage is being able to easily introduce complex new designs to fabricators. Nearly everyone can visualize a new design more easily in 3D. It is a lot harder to install that nozzle 180 out when given shaded isometric views to reference.

The 2D vs. 3D argument is a lot like the CAD vs. board drafting argument from so many years ago. Sure you have to retrain your drafters, but once they are trained productivity increases, mistakes decrease, and design changes are easier to make.

 

[jistre]

While it's true that I've never built a pressure vessel before, that does not change the abilities of 3D solid modeling packages to streamline drawings once set up.

Granted, they don't do code calculations, but as you said, you've got yet other programs to do that for you. I was specifically referring to bhuffman's question about saving drafting time in DETAILING the vessel. Nowhere in there did he mention doing any of the code calcs or vessel design that comes before the drafting of prints.

Of course, we all need to be careful when we're talking about models here to differentiate the strictly geometric solid models that I and others are and the models that waskillywabbit is talking about. The models he's talking about are actually modelling the performance and stresses in the operational exchanger, and for that, 3D packages are definitely the wrong tool.

 

[3dwaytogo]

Brian(waskillywabbit), please don't take my words as bias, they come from doing drawings manually, and yes I have done basic vessle design in autocad way back when, my backgroud is heavy process/bio pharm, and petro chem. I have done detail design in Autocad and used Compaid to get my isometrics out the door if you have ever heard of that system, my present system is 3D, there are many sytems/software packages for 3D, PDS, PDMS, REBIS, Solid works, etc, and there are specialty companies that specialize in equipment, archetectural as well as supports and stress analysis, my whole point was that at the daratech convention the buzz was about 3D and how only 55% of companies have come around to switching from the 2D world to 3D, this puzzled many people, mainly Louis Gary Lamit(moving from 2D to 3D CAD for Engineering Design), the companies that switched did not know why it took them so long to reap the benefits of the 3D systems, the other companies are switching slowly, it was your comment that most people make reference to, I was trying to point out that bias to you and to try and get people to talk about 3D and all the benefits too numerous to mention, but I will give you some, owner/operators believe it reduces construction and engineering costs and shortens design time, along with Real Obstructions that you can view while in the model(one of the biggest advantages), 2D drawing extraction, isometrics, B/M, spooling packages, stress analysis transfers to other systems, Scheduling, and all the way to decommissioning, yes PLANT LIFE CYCLE data management, there are many other benefits, I am just trying to pass along the ideas, we all would like to stay ahead of our competition, at the daratech conv. they feel 3D is the way for companies to blow away their competition, I only agree with them and happily pass on that knowledge with you and our fellow workers out here.
Thanks, Rich

 

[3dwaytogo]

there was another quote that I wanted to comment on from Brian, you mentioned "What works on paper or even the computer does not always work in the real world (fabrication)", this is true and applies to all Design Disciplines, but things are changing and expanding, I merley wanted to point out the industry is changing and in the process of more changes, to be open to these changes will be beneficial to those that are open, if that makes any sense in that context.

 

[vesselguy]

Nice boxing match going on here boys.

As an engineer, in the old days (late 80s), I started by doing manual drafting/layout of vessels and exchangers on the board for a year before I was allow to handle a vessel package. Damn it, nowadays new grads are made Project Engineers; unfreaking believable!!! Few months later, I rolled out ACAD for 2D CAD for equipment layout. I have also been trained on 3D CAD and have done some FEA modelling. Although I have not done any CAD in the last 10 years, I guess I'm still qualified to comment on this.

I agree with 3dwaytogo. Many engineering software (Compress, HTRI, etc) all generate 3D models as an output. The 3D CAD software will generated your typical 2D plans complete with BOM. Although not all software are equal so research before purchase so it will suit your preference. The auto BOM update of the database is also the other bonus, and I believe this is a common feature in many vessel modeling package today. Of course, clash checking is so easy on 3D model. Also,the 3D model may be able to be transfered into ANSYS for FEA.

Long and short is, go 3D but chose the package carefully. I know some people, myself included many years ago, have a hard time accepting changes, but if you don't change then the world moves on without you.

 

[LSThill]

Technical Review;

ISO 15926 Part 7 – Implementation of ISO 15926

Vessel drafting: 2D vs. 3D:

ISO-15926: Integration of lifecycle data for process plants including oil and gas production facilities

 

[FSB01]

I have used both 2d and 3d design for pressure vessel. My personal choice would be 3d.
However I would not recommend it to every pressure vessel fabricator.
Advantages of 3d:
- mistakes are reduced as designer is working with model, and each part is “assembled” into model same way as it will be in fabrication stage
- BOM is linked to the model, therefore less mistakes
- After you have a 3d model it is easy to create any draft view for detailing
- Weight and some other parameters are easy to get from the 3D model
- It is possible to modify similar design very quickly
- Sales pitch, customers loves 3d pictures of models.

Disadvantages of 3D for pressure vessel design:
- Most important thing, if 3D software is not implemented properly, all advantages becomes disadvantages.
- Good cad operator is not always a good pressure vessel designer. Designers with lots of an experience are used to work with 2d and sometimes are not willing to switch. They will be very slow at the beginning.
- Company database of old designs will not be as useful, as all designs shall be done again in 3D. There is no easy and smooth 2D to 3D transition.

I would still recommend 3D, however management needs to have realistic expectation. At beginning 3D will be slower and more complicated. But down the road it can generate better design and more profit.

 

[11echo]

I'm and old school designer and I'm on the fence on this one! Things have been built a lot of years without any 3D input! ...And I believe they can/could continue that way. However generating a drawing in a "smart" 3D program that can automatically generate MTOs and point out "clashes" makes alot of sense! The bottom-line, I'd take what "any" computer sales person says with two grains of salt, go talk with the poor slobs (with experience doing it the old way) what they feel is a good choice, and go from there.

 

[waskillywabbit]

I use 3D software daily for fabrication design to mainly check for interferences, but I see no need to implement that 3D into fabrication in the form of drawings. If there is some confusion about a PV design, computers are still no substitute for good old fashioned face to face communication between designer and fabricator. We have become more technologically advanced and actually truly communicate less.

I also learned drafting with a good old fashioned pencil before AutoCAD was even taught in college, so if that makes me an archaic old fart so be it, but I am not that old. Nowadays greenhorn graduates have no clue how to draw anything or do any calculations if the power goes out. Not all change is GOOD!



Brian