AutoPipe Modeling Problems

Hi,

I started learning AutoPipe about a week ago. I am trying to model and set up the analysis for a piping system (reference pages attached from "Applying the ASME Codes Plant Piping & Pressure Vessels" textbook, by James. A Wingate).

I started modeling the geometry at Node A00 (Node 5 in the example problem in the book), but what I have modeled does not look OK.

I am  not sure on how to model  the following elements : H/X 10" flange connection, the 10"x12" reducer, the reducer attached flange and the flanged  30" strainer.

Shall I define the 10" H/X flange connection on a 10" segment and then the 10"x12" reducer on a 12" segment?

I have included here a copy of the pages from the above mentioned book. I would appreciate any suggestions and tips  on how to properly model these elements.

Regards,

Bogdan ChivulescuPDF

  • Hi Bogdan,

    As we have already discussed, here is the response to your questions.

    Flanges are single point  components with no length, but take into account the flange weight and the SIF of the welded connection.  The link below has more information, including a recommended method to model a flange and include the hub length.  https://communities.bentley.com/products/pipe_stress_analysis/w/pipe_stress_analysis__wiki/8398/b-flanges-piping-components-modeling-approaches-tips-techniques-used-in-autopipe

    The component from A00 to A05 in the model looks like it was inserted as a run.  If it needs to be a reducer, it needs to be inserted as a reducer and then a new Pipe Identifier has to be defined for the new 10” pipe.

     Here is a link to help define the strainer.

    https://communities.bentley.com/products/pipe_stress_analysis/w/pipe_stress_analysis__wiki/28859/n-how-to-model-a-strainer-filter-in-autopipe

       
    This is a test

  • Hello Bogdan, 

    In addition to Jessica's comments above, please see the attached AutoPIPE CONNECT v.11.01.00.23 model.

    There was insufficient information to model this example. There is no information on:

    1. The length of the valve at Node 60. I guessed.

    2. Piping Code year to be used. Assumed 2016.

    3. Of insulation density used, assumed 11 lbs/ft3.

    4. AutoPIPE uses seamless pipe for all library data, use pipe properties long e weld factor to account for long welded pipe.

    5. Not clear if Hot Allowable etc should be 20ksi or 17ksi.

    6. etc.. 

    Do not use this model in production unless you have completely reviewed and found it to be correct.

    Regards,

    Mike Dattilio
    Bentley Product Advantage Group Analyst
    AutoPIPE Product Line Bentley Systems, Inc.FIG 3-1 Piping Stress Analysis Isometric Sketch_Archive.zip

  • Hi Mike,
     
    Thanks for your email.
     
    These are not for real projects. I am trying to learn AutoPipe. I have it available until Saturday.  To learn faster AutoPipe I try to relate to my experience from Caesar II  piping stress work, Caesar II tutorials/lessons and other materials (piping stress books) which I used in the past. Basically, I am using several piping models from Caesar II tutorials and other manuals to learn AutoPipe. That is a good practice for me to see how close the results matches.
     
    Attached here is the problem statement for that model you have modeled below. It is from a piping textbook. See FIGURE 3-1: Piping Stress Analysis Examples Isometric Sketch.
     
    Could you please sent me the file of this model ?
     
    Regards,
     
    Bogdan Chivulescu,P.Eng.
    Mechanical Engineer
    Regina, SK, Canada
    Tel: 1(780)996-5608
     
    Sent: Tuesday, September 26, 2017 at 3:24 PM
  • Good Morning Mike,
     
    Thank you for that AutoPipe file you sent me yesterday.
     
    I have a few more questions. See the attached print screens.
     
    In a brief presentation about spring hanger design process you have said that "anchor may be released in any direction" and that is optional. First, what is the purpouse of releasing the anchors when sizing a spring hanger.
     
    Second, why is this optional?
     
    Third, if there are several anchors in that piping system which one can be released? What would be the criteria to consider when releasing an anchor in that situation?
     
    In the same brief presentation you have said that "decide if analysing by hot or cold load design.." When would you use one or the other load design ? 
     
    Bogdan Chivulescu,P.Eng.
    Mechanical Engineer
    Regina, SK, Canada
    Tel: 1(780)996-5608
     
     
    Sent: Tuesday, September 26, 2017 at 3:24 PM
  • Hi Bogdan,

    A common reason for releasing the anchor might be because the piping is attached to equipment near where the spring hanger is located, and the user might prefer to have the spring hanger take more of the weight of the piping system than than the nozzle connection to the equipment.  This is further explained in the help section: Help > Contents> Contents Tab> Modeling Approaches> Anchors>  Modeling Approaches> Anchor Releases For Hanger Selection.  The anchor release is optional because it would only be used in specific situations, like the one mentioned above.

    For some applications it is preferred to use a Cold Load approach.  The idea of the Cold Preload is that as the spring goes from the cold to the hot condition, it is balanced in the hot operational state.  It provides for more balanced loading on equipment during installation in systems involving hot gas piping around pumps, or gas piping around compressors or steam piping around turbines.  In this case the load calculated in the Gravity case is taken as the cold load.  The calculated Hot load is then less and the load variation calculation also changes.  This AutoPIPE Wiki has more information and an example.

    Thanks,

    Jessica Alegre

       
    This is a test