PLTP Guide - Piping Loadings Transfer Program

PIPING LOADINGS TRANSFER PROGRAM
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User's Guide
User’s Guide
PIPE LOADINGS TRANSFER PROGRAM

By

Michael Fung and P K Fung



1. Introduction


The Pipe Loadings Transfer Program transfers an output data from piping stress analysis results to an input data of a structural analysis program. One of the purposes of the piping stress analysis is to provide pipe loadings for the structural analysis. These pipe loadings are composed of vertical loads and horizontal loads which are generated from weight, thermal and occasional loads of a piping stress analysis. In general, the piping stress analysis program will generate a large amount of data for a piping system such as deformations, stresses, forces and moments in each piping element, as well as the restraint reactions to equipment nozzles and the pipe support structure. The restraint reactions listed in an output file of the stress analysis results are the useful information to the structural analysis. This program is developed to give a systematic data transformation from piping stress analysis results to a pipe loading input file of a structural analysis program. The program flow chart is shown in Figure 1.

  

1.1 Piping Stress Analysis Results Transfer to Civil and Structural Department


In general, the restraint reactions of piping stress analysis results are transferred to civil and structural department by means of marked up isometric drawings and restraint reaction tables from the stress analysis computer printout. The support nodes generated from the stress analysis program are marked-up on isometric drawings and the loadings of support nodes are printed-out in a restraint reactions table. Sometimes, the stress engineer also marks-up the maximum loadings on isometric drawings.

The restraint reactions are the pipe loadings acting on the beams of a structural frame; for that reason, the restraint reactions of the piping stress analysis result become the pipe loadings in the structural analysis program.


1.2 Transfer Procedures


In every project execution, there will be some kind of procedures to be developed in order to transfer the pipe loadings from the piping department to the civil and structural department. These procedures are developed for the quality assurance and quality control during a project execution.


Because a large amount of data to be marked-up on isometric drawings and to be retrieved by structural engineers, troubles often appear during the transfer process.


1.3 Problems in Existing Pipe Loadings Transfer System


The problems in the existing pipe loadings transfer system are caused by dealing with a large amount of data through several engineering discipline personal in a project. For example, piping stress engineers carry out stress analyses based on the pipe supports located by piping designers and the stress engineers may not have any idea about the structural layout. On the other hand, structural engineers after receiving the stress marked-up isometric drawings are often struggling to find out where are the pipe support locations in the piping structure. They may spend a lot of time to go through pages of marked up isometric drawings and the related restraint reaction tables to look for the piping forces for each pipe support. Furthermore, these piping forces at pipe supports have to be re-input manually to the structural analysis program.  This tedious work has to be repeated again and again for every pipe support in the structural system.


The Pipe Loadings Transfer Program is developed to eliminate this tedious work and to streamline the data flow in order to save engineering time and reduce errors during the data transfer process. Many features such as easy to search, verify and edit data will provide the maximum flexibility to improve the data transfer process and to achieve a better structural analysis.



1.4 Improvement of Data Transfer


The Pipe Loadings Transfer Program is created for the improvement of data transfer by introducing a pipe support number at the pipe support in a plant design model. A pipe support number represented by three-dimensional coordinates in a plant space is introduced to identify the pipe support location in a plant design. A piping designer will locate the pipe support with a pipe support number (called a tag number) in a plant design. This tag number can be picked up by the plant design software in a file export menu of a PXF [1] file or a PCF [2] file. When the stress analysis program interfaced with a plant model using a PXF file or a PCF file, it will treat this tag number location as a pipe support location.  Then the analysis results of a stress analysis program will show the restraint node number with a tag number at the support location in a restraint reactions table as shown in Figure 1.


For a piping stress analysis, the analytical results are presented in an output file with an out extension. The restraint reactions table in an output file will contain node numbers, tag numbers, and forces of pipe supports. All these information will form a unique database system for a pipe support and the data contained in this system unit can be manipulated in later analysis.



2. Program Features


In the Pipe Loadings Transfer Program, each database unit can be edited, or searched based on pipe support numbers, restraint types or beam numbers respectively. In a physical sense, every pipe support is attached to a piping structure, and each beam on a pipe rack or on a piping structure may contain a number of pipe supports. This Pipe Loadings Transfer Program has a unique feature to link pipe support numbers to a beam number, as a result, this program has the ability to group all pipe support loadings, which are belong to a beam to form the beam loadings of a structure.




2.1 File Data Input



The Pipe Loadings Transfer Program inputs the restraint reactions output files in one at a time or in a group of many files. Each restraint reactions output file with an out extension contains node numbers, pipe support tag numbers, and forces of the restraints. If some information is missing, the missing information can be added or corrected, and then the modified information will be saved in the file.



    2.2 Pipe Support Number


A pipe support number (called a tag number) is placed at the pipe support location on a piping model by a piping designer. In a piping model, this tag number is inserted to the point on the centerline of a pipe at the support location and the coordinates of this point are used to designate as the tag number of a pipe support. This tag number contains eighteen digit numbers which are separated into three groups by hyphens. The first group of six digits represents the last six digits in a desired unit in the east or west coordinates of a plant. The second group of six digits represents the last six digits in the north or south coordinates of a plant. The third group of six digits represents the last six digits of a plant elevation. These numbers are the last six digits in a desired unit of a pipe support point in the X, Y and Z coordinate system of a plant.


These pipe support numbers can be presented on the isometric drawings. For easy viewing purpose, the six digits coordinates will be changed to three digits coordinates to show on isometric drawings. The tag number is a convenient pipe support designation for piping designers, stress engineers, structural engineers, construction and plant operation and maintenance personal to follow the same symbol.



    2.3 Beam Number


The start point coordinates with a beam direction are introduced to identify as a beam member of a pipe frame structure. The start point coordinates of a beam number have an eighteen digit numbers format similar to the pipe support number.


In a 3D structural model, a structural member is defined from its start point coordinates to its end point coordinates. It will be convenient to follow a rule to include a positive increment to identify the length of a structural member. To apply this rule in consistent with the plant design software is to define the coordinates of a member in a direction from the west to east coordinate, or from the south to north coordinate to cover the span of a beam or from a low elevation to a high elevation to cover the height of a column. By doing this way, the coordinates of a structural member will have a positive increments from its start point to its end point.



   2.4 Link Pipe Support Numbers to a Beam Number


In preparing a structural analysis, one of the tasks is to find out what are the piping loads acting on the beam of a pipe frame structure. Because the format of a beam number is similar to the format of a pipe support number, once a individual beam is chosen, then the elevation and the direction of the beam is determined, therefore those pipe support numbers with the same elevation and the same directional coordinate along the beam can be linked together as a group to form the pipe supports on a beam and the loadings of these pipe supports become the beam loadings. There are two icons to cover this type of operations: the Batch Run icon is for collecting the beam loadings and the Stringer icon is for collecting stringer loadings. The beam length tolerance for the Stringer will be less than 0.1 m to obtain good results.

 

The Pipe Loadings Transfer Program will link those pipe support numbers in a group for a beam number in the procedures as follows:


  • Click on the Links icon to open the Links window. In this window, the beam numbers and the pipe support numbers are presented in three digits as shown in Figure 2;

  • Click on the Batch Run button to open the Links-Batch Run window, and select the pipe frame orientation along the X or the Y direction, then fill in the beam span;

  • Click OK button to complete the search for beam loadings

  • These operations shall group all the pipe support numbers to the related beam numbers together to form the beam loadings for a structure.



    3. Search Information


    In a structural analysis, some questions are often to come up if all pipe loadings acting on a beam were completed, correct, or required any updated information to fulfill the structural analysis requirements.


    The Pipe Loadings Transfer Program has the facility to search the information based on beam loadings, pipe support loadings, or horizontal loadings such as guide loads and anchor loads on a structure as shown in Figure 3.


    3.1 Search Beam Loadings


    When the Links window is opened, the following procedures shall be carried out to obtain loadings information on a beam:


    • Highlight a beam number and click on the Beam Details button, then all the beam numbers linked to the pipe support numbers will show in a listing box;

    • Invoke each beam number to show all pipe supports on a beam and to list the stress run files, support numbers, pipe support nodes and restraint types;

    • Invoke the pipe support numbers to show pipe support loadings  Fx, Fy and Fz on a monitor as shown in Figure 4;

    • 3.2 Search Pipe Support Loadings


      When the Links window is opened, the following procedures shall be carried out to obtain the information on a pipe support number:


      • Click on Pipe Support Details button, and then all the pipe support numbers will show in the listing box as shown in Figure 5;

      • Invoke each pipe support to show the pipe support loadings on the monitor with the node number, the restraint type and the file date for a pipe support number.

      • 3.3 Search Restraint Loadings


        It is useful for a structural analysis to obtain the horizontal piping forces acting on a pipe support structure. This task can be accomplished by searching the restraint types of pipe supports on the search window as shown in Figure 3. These restraint types include guides, line stops and V-stops as defined by the stress analysis program.


        • Invoke the restraint type such as a Guide, a V-Stop, or a Line stop, then all the source files, node numbers and structure numbers will show on the monitor;

        • Highlight the source file, and then the forces of the restraint will show on the monitor.


        • 4. Transfer Pipe Loadings to a Structural Program


          The Risa-3D [3] and S-Frame [4] structural analysis program have the Excel format for inputting joint loading or point loading data; the joint loadings or point loadings along a beam can be easily transferred to the structural program by using the copy and paste feature.


          4.1 Point Loadings


          The loading acting on a beam is called as point loadings. The location of a loading point on a beam is determined by the ratio of a support distance dividing by the full span length of a beam. This ratio can be obtained by invoking the structural Analyze button when the Beam Details window is opened as shown in Figure 6, and the detail procedures from inputting data files to creating structural models are presented in Figure 6A, Figure 6B, Figure 6C and Figure 6D respectively. For accuracy purpose of the structural analysis, six digits are employed in this window for all calculations.


          • Invoke the beam Analyze button and choose a specific beam direction (i.e. X or Y coordinate);

          • Fill in the beam span length;
          • Invoke the calculate button to obtain distance ratios for all pipe supports, then invoke the Excel button to show the Beam loadings, Summary Restraints and GA Loadings tables in an Excel format;
          • Highlight the useful data, then use the copy and paste method to transfer the piping loadings to a structural program.

          • This is the most efficient method to transfer the pipe loadings from stress analysis results to a structural analysis program.


            4.2 Joint Loadings


            The loadings acting at the joints of pipe support nodes are called as joint loadings. In order to obtain a better picture of the joints distribution in conjunction with the marked-up isometric drawings, it would be a good idea to input only one stress out file each time. The joint loadings shall be used for a pipe which is located outside of a pipe rack or for base supports which are located on the ground.


            • Click on a Node Force icon to open a Node Force window as shown in Figure 7 and  Figure7A shows the Joint Loadings Flowchart;

            • Fill in the data directory location and file name for the DXF file;

            • Click on the Sort Coordinates, then select X or Y direction for sorting,
            • If the Summary button is chosen, the Joint Force Table will show the maximum nodal forces in Excel format.

            • If the Risa button is chosen, the Risa Joint Force Table will show in Excel format, save the DXF file, then use the copy and paste method to transfer the joint loadings to a structural program.


            • 5. Beam Number Generator


              The beam numbers and the member numbers of a structure can be automatically generated by the beam number generator.


              5.1 Generate Beam Numbers and Member Numbers


              When the beam number generator window is opened as shown in Figure 8, the following procedures shall be carried out to generate beam numbers and their related member numbers:


              • Fill in the origins of a structural frame at its X, Y and Z coordinates;

              • Fill in the increments of the structural grid in the eastward or northward and column height respectively. Use the @ symbol to define a series of equal increments;

              • Invoke the generate button to list all beam numbers and their related member labels in the listing box as shown in Figure 8;

              • Click Save button to store the beam numbers and their member numbers in the system.

              • 5.2 Generate Structural Model


                When the structural model window is opened as shown in Figure 9, the following procedures shall be carried out to generate a structure model:


                • Fill in the origins of a structural frame at its X, Y and Z coordinates;

                • Fill in a beam span and their increments of beam numbers in the eastward, or northward and the elevation respectively for a structural grid. Use the @ symbol to define a series of equal increments;

                • Invoke the generate button to list all structural members in the listing box as shown in Figure 9;

                • Save DXF file in the required location for the structural model file.

                • 5.3 Import a DXF File


                  After the DXF file for the structural file being imported to the structural program, the joint loadings can be transferred to the structural program as shown in Figure 10 and the point loadings can be transferred to the structural program as shown in Figure 11 for the Risa-3D example and Figure 12 for the S-Frame example.


                  6. Conclusions


                  The pipe loadings transfer program develops a unique database to transfer pipe support loadings from stress analysis results to the pipe loading input file of a structural analysis program.


                  • It is time-consuming in the existing system by transferring a large amount of pipe support loadings manually from stress analysis results to the pipe loading input file of a structural analysis program;

                  • The Pipe Loadings Transfer Program is developed to build an unique database in order to satisfy the need of the pipe loading input data for a structural analysis program;

                  • The concepts of a pipe support number and a beam number were introduced to make the data manipulation possible;

                  • The beam number generator and the creation of a DXF file for a structural model provide a convenient tool for the program operation.
                  • This is the data file transfer method to map the design data from one program to another program; as a result, the data transfer errors will be reduced.


                    A series of projects have employed the Pipe Loadings Transfer Program and proved that this program is reliable and applies the most advance technology in a plant design. The advantage of using the Pipe Loadings Transfer Program is simple, fast and accurate.




                    REFERENCES

                    • [1] AutoPIPE Tutorial Manual, Bentley Systems, Incorporated
                    • [2] Caesar II, User’s Guide, Intergraph
                    • [3] RISA-3D, User’s Guide, RISA Technologies
                    • [4] S-Frame, User’s Guide, S-Frame Software



                    • APPENDIX A


                      S-FRAME DATA TRANSFER


                      1. Open S-Frame program and import a DXF file;

                      2. Set Member field to 0, choose OK to open the OPEN DXF dialog;

                      3. Select a filename and choose Open;

                      4. Click on View Geometric Label icon to open Geometric Labels window, highlight Element Information option, and Member Numbers;

                      5. Confirm the relationship between beam numbers and member numbers

                      6. Click Loads and click New Load Case icon to input the required load cases;

                      7. Click on Spreadsheet and switch to Loads, then choose loading type case;

                      8. Click on Member Loads icon

                      9. Apply copy and paste method to transfer pipe loadings to S-Frame program.



                      10. APPENDIX B


                        RISA-3D DATA TRANSFER


                        1. Open Risa-3D program and import a DXF file. The following procedures shall be carried out:

                          • Click on the Global menu;
                          • Open the Solution tab;
                          • Choose vertical axis in Z;
                          • Click on Apply and OK button, than imports the DXF file.

                          • Select DXF units to millimeter, Scale Factor to 1 and CAD vertical Axis to Z, then choose OK to input the structural model;

                          • Rotate the model 180 degree around the Z axis to obtain the world coordinate system which in line with the AutoPlant system;

                          • Click Basic Load Cases icon and input loading type case in Risa-3D program;

                          • Click on Spreadsheet, Select List and highlight the  Point Load icon  or Joint Loads icon to open basic load spreadsheet;

                          • Apply copy and paste method to transfer pipe loadings to Risa-3D program.



                            1. APPENDIX C


                              DATA TRANSFER EDITING


                              The pipe support number called tag number represents the support point coordinates on

                              the center line of a pipe at the support location, and the numerical values present the last
                              six digits in millimeter of the X, Y and Z coordinate of a designed plant.


                              After the pipe loading being transferred to the structural analysis model, each loading point shall show the same coordinates as the tag numbers. Therefore the tag number shall be used for loading editing if the stress analysis results had been revised.


                              A start point coordinates of a beam with a beam direction is introduced to identify a beam member. Some time, the user might wants to modify the beam coordinate with the revised value to the beam coordinate to obtain the correct results in the beam loading Analyzer window.

                              The Pipe Loadings Transfer Program provides 100 % accuracy on magnitude of loadings.

                              The maximum error on pipe support location is half millimeter.


                              The advantages of using Pipe Loadings Transfer Program are accuracy and speed to

                              transfer pipe loadings from stress analysis results to the structural analysis model.





                              APPENDIX D


                              EXCEL DATA FILE



                              There are three types of Excel data files: beam loadings, structural grid loadings and GA loadings.


                              1. Beam Loadings – Contains beam names and beam numbers. Pipe loadings acting on each beam are presented for the maximum load due to all the loading cases.

                              2. Structural Model Loadings – Contains the Summary of restraints for a structural frame. The vertical loadings and guide loadings are combined in the combined loadings table and line stop loadings are shown in separated tables. Using copy and paste method to transfer pipe loadings to the structural program.

                              3. GA Loadings – Contains pipe loadings distribution based on the general arrangement drawings. This table lists the information on ratio, restraint type, forces, node number, member number, beam number and file name. This is a convenient form for record and checking.

                              4.          GA Loadings present the loadings on each level of a structural model. The pipe loadings for a structural frame are sorted based on the elevation, the ratio and the northward or eastward direction respectively.

                                         These loadings present in Excel format shall be used in conjunction with the general arrangement drawings from the plant design software to give a visual view of loadings distribution based on the magnitude and location for each floor.



                                APPENDIX E


                                APPEND AND MERGE




                                In order to obtain the pipe support loadings on beams and stringers of a structure model, two loading models shall be built on separated Risa-3D models, and then the append and merge features shall be used to combined them together to form a pipe loading model for a structural frame.  To avoid any confusion on model append and model merge, the order of basic load cases shall be the same for beam loading model and stringer loading model. There will be a lot simpler if the redundant members in the beam and stringer model were deleted first before the operation of append and merge as follows:


                                1. On the stringer loading model, open the Delete Items icon window and check the Delete Selected Members box, then press the Apply button to close the window.

                                2. Delete all the redundant beam members.

                                3. Go to File, Append to highlight the beam loading model file and click Open to append.

                                4. Select all members active and click the Model Merge icon to apply the merge function.



                                5. FIGURES

                                  Figure 1. Flow Chart of Pipe Loadings Transfer Program

                                  Figure 1. Flow Chart of Pipe Loadings Transfer Program




                                  Figure 2. Link Window

                                  Figure 2. Link Window




                                  Figure 3. Restraint Type Details Window

                                  Figure 3. Restraint Type Details Window




                                  Figure 4. A Beam Listing Window

                                  Figure 4. A Beam Listing Window




                                  Figure 5. Pipe Support Number Details Window

                                  Figure 5. Pipe Support Number Details Window




                                  Figure 6. An Analyze Window

                                  Figure 6. An Analyze Window




                                  Figure 6A. Points Loadings Flowchart

                                  Figure 6A. Point Loadings Flowchart




                                  Figure 6B. Import Files

                                  Figure 6B. Import Files




                                  Figure 6C. Create Structural Grid and Beam Numbers

                                  Figure 6C. Create Structural Grid and Beam Numbers




                                  Figure 6D. Link Pipe Support Numbers to Beam Numbers

                                  Figure 6D. Link Pipe Support Numbers to Beam Numbers




                                  Figure 7. A Node Force Window

                                  Figure 7. A Node Force Window




                                  Figure 7a. Joint Loadings Flowchart

                                  Figure 7a. Joint Loadings Flowchart




                                  Figure 8. A Beam Number Generator

                                  Figure 8. A Beam Number Generator




                                  Figure 9. A structure Model Generator

                                  Figure 9. A Structure Model Generator




                                  Figure 10. Joint Loadings

                                  Figure 10. Joint Loadings




                                  Figure 11. Pipe Support V-Stop Loadings Transferred to a Structural Frame

                                  Figure 11. Pipe Support V-Stop Loadings Transferred to a Structural Frame




                                  Figure 12. X-Loads on Pad L

                                  Figure 12. X-Loads on Pad L




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