CAEPipe - New User - Q on materials libraries 1

[Pipeline1972]

Hello all,
I'm a new user with CAEpipe (demo version), and already I have a question regarding the materials that can be used in CAEPipe. It seems there are no libraries available for plastics like PVC, or PVDF. I contacted the tech support, and I was told they don't supply non-metallic piping libraries. They didn't tell me why, but they did say i can create my own. That doesn't make me want to cash out for the full version of the software, but anyway... I'm trying to create a new library, and i find myself stuck with the "Type" of material. The available choices are not helpful to me, and i can't create a new type, I think.

Anyone got some advice?

Thanks!

Process - Piping
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[Pipeline1972]

It looks like CAEpipe is useless for thermoplastic piping installations... hmmm...

Process - Piping
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[LSThill]

contact SST SYSTEMS, INC. Customer Support

http://www.sstusa.com/support.php

L S THILL

 

[SNORGY]

Pipeline1972:

I must admit that I myself use CAESAR II and not CAEPIPE, but in general, irrespective of the software being used, if there is provision to add a user-defined material into the library, I would have no problems with doing it other than the following cautions (forgive me if you know all of this already):

(1) Design Code treatment is likely to be different than it would be for metallic pipe; if there are no thermoplastic materials databases, then neither might there be the provisions to correctly handle the design calculations *by the Code*.
(2) I think a lot of "standard" thermoplastic pipe materials run into design limits at about 71 C temperature.
(3) Hydrostatic Design Basis (HDB) is often the primary concept used towards pressure design.
(4) A person can conceivably approximate the elastic modulus, linear expansion coefficient, and other material properties to model the pipe, but to do this correctly probably requires a lot of confirmation from vendor experts whose opinions and recommendations are likely to vary. So, rather than adding one or two materials to the database, you might end up having to enter a great deal more on a vendor-by-vendor or product-by-product basis. There are, however, governing API standards that you might be able to default to, but then you are making some generalizations.
(5) Some of the thermoplastic pipe material vendors have pretty good technical manuals, available from their websites, in support of their products that can be of considerable assistance towards estimating material properties. KWH Pipe comes to mind.

So, regardless of whatever provisions are in the software to add materials to the database, proceed with caution and back up your rationale in the event of "curious" results.

Regards,

SNORGY.

 

[Pipeline1972]

Thanks Snorgy. We are here in the process of evaluating CAEpipe for use in thermoplastic piping system.

The issue with creating new libraries, is this:

Looking at the equations for non-metallic piping (B31.3), we see a different equation than the one used in CAEpipe, which is for metallic piping: (P=(2SEt)/(D-2Yt)

E is a joint quality factor (material property). No E available for non-metallic piping.
Y is a pressure coefficient, depending on the temperature. No Y available for non-metallic piping.

Maybe we can trick the program and tell it E has a value of 1 and Y a value of 0.5. We are not interested in the internal pressure at this point, just the thermal expansion.

We did all the calcs manually, and now we're looking at how CAEpipe can be of any utility.

Process - Piping
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[SNORGY]

Looking at B31.3 A304.1.2 Equation 26a, that's what I would be inclined to try.

The CAEPIPE equation that you have cited is the same as B31.3 304.1.2(a) 3a within the limits stated and with W = 1.0. It's obvious from your post that you have already observed that.

CAEPIPE's been around for a long time; I think it might even pre-date CAESAR II. The first version I remember seeing was CAEPIPE v3.11 for DOS back in the early / mid 1980's. The software is undoubtably good.

Regards,

SNORGY.

 

[Pipeline1972]

I just heard back from Kpipe, and they basically told me, for thermal evaluation purposes only, not to worry about E and Y, just input the thermal data in the new material library, and to keep in mind the results for allowable pressure will be off. The thermal expansion shouldn't get affected.

I'm only interested in thermal expansion, so that's fine with me.

Of course, finding a calculation tool that would do the pressure analysis, thermal expansion, and seismic expansion for thermoplastic piping... now that would be something!

DOS? Talk about a trip to Nostalgia City!

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[SNORGY]

Yes...DOS.

Those were the days...when something went wrong, an error message occurred that actually made sense and I could usually fix it with EDLIN to modify a CONFIG.SYS or AUTOEXEC.BAT file or a DEVICE=xxxx.SYS command. Sometimes I would have to use Norton Utilities or PC Tools. That was back in the days when the first computers we saw in the office were 8088 units at 4.77 MHz and a 256 KB RAM limit; two such units were shared by 30 engineers. The upgrade to TURBO XT at 10 MHZ with 640 KB RAM was huge. HYSIM runs no longer had to be completed by starting them at 4:30 and letting the machines run overnight, and a 100-node CAESAR II file converged to a solution within twenty seven minutes.

Than along came Windows and now I can't fix anything, but when things happen, they sure happen fast.

Regards,

SNORGY.