Tutorial for Modeling and Results Review - Problem 1

The best way to learn CAEPIPE is to try it yourself. In this tutorial we will create a simple model to help you understand the use of CAEPIPE. The details of the model are shown below:

You will learn how to:

1. Enter Title

2. Select Analysis options (piping code etc.)

3. Deﬁne Material, Section and Loads for the model

4. Input Model Layout

5. Select Load Cases for Analysis

6. Analyze

7. View Results

Start CAEPIPE. Click on the option “File > New” from the layout window. The “New file” dialog opens.

From the “New ﬁle” dialog, select the type of the new ﬁle as “Model (.mod)” ﬁle. This opens two independent windows: “Layout” and “Graphics”.

Layout window

Graphics window

Adjust the size of the windows to ﬁt your desktop such that you can view both comfortably at the same time.

1. Enter Title

Type “Sample Problem” as the title in the ﬁrst row that contains “Title =”. Press Enter.

2. Select Analysis options (piping code etc.)

Click on the “Options” menu and then select “Analysis” (Options > Analysis) to specify options for analysis.

This opens the “Analysis” Options dialog.

On the Code property page, select “B31.3 (2024)” for Piping code. Then click on “OK” to close “Analysis Options” dialog.

3. Deﬁne Material, Sections and Load Material

Click on “Matl” in the header in the Layout window (or press “Ctrl+Shift+M”)

This opens up the “Materials” list in a separate “List” window. Position and resize the list window as you desire. Click on “Library” button on the “Toolbar” (or choose File > Library).

The “Open Material Library” dialog is shown

Select “B313-2024.mat” as the library ﬁle to open by double clicking on it. The available materials in the library are shown.

Double click on “A53 Grade B (SEAMLESS)” material to select it. The properties for this material are transferred to the material in the List window. Type “A53” for material name and then press “Enter”.

Sections

Select “Sections” from the “Misc” menu of the List window (or press “Ctrl+Shift+S”).

The “Sections” list is shown. To enter the ﬁrst section, Type “8” for section name and press “Enter”. The Section Properties dialog is shown with the section name 8.

The Section Properties dialog (“Section #1”) is shown with the section name 8.

Click on the “down arrow” of the “Drop Down” combo box for “Nominal diameter” and select 8” for “Nominal diameter”. The “Outside diameter” (8.625”) is automatically entered.

To select the schedule for the 8” pipe, click on the “down arrow” of the “Drop Down” combo box for “Schedule” and select 80 for “Schedule”.

The “Thickness” (0.5”) is automatically entered.

For “Insulation density”, click on the “Insulation” button or Press “Alt+I”.

A table of “Insulation materials and their densities” is shown.

Double click on “Calcium Silicate”. The “Insulation density” (15.0 lb/ft3) is entered on the “Section” dialog. Type 2 (inches) for “Insulation Thickness” then press “Enter” or click “OK” to enter the ﬁrst section.

Now repeat the process for the second section.

In row # 2, type 6 for section “Name” and press Enter. The “Section Properties” dialog is shown with the section name “6”. Select 6” for “Nominal diameter”, STD for “Schedule” and 2” Calcium Silicate for “Insulation”. Press “Enter” or click on “OK” to enter the second section.

Load

Select “Loads” from the “Misc” menu (or press “Ctrl+Shift+L”).

The “Loads” list is shown. To enter the ﬁrst load, Type “1” for “Name”, Tab to “T1” and type 600, Tab to “P1” and type 200, Tab to “Desg. T” and type 800, Tab to “Desg. Pr.” And type 250 and Tab to “Speciﬁc gravity” and type 0.8. Then press “Enter”. That is it! The load is entered. (Alternately, you could have pressed “Ctrl+E” on the ﬁrst row and typed in the same information in a dialog box).

Note:

Design Temperature and Design Pressure should always be greater than or equal to the Operating Temperature and Operating Pressure (T1 and P1 for this tutorial).

Design Temperature entered will be used to compute the allowable stress for material while computing the Allowable Pressure as per the piping code selected.

The Allowable Pressure computed as per the piping code selected is then compared against the Design Pressure entered above and reported in the Code Compliance results.

In addition to the above, starting “CAEPIPE V.12.10”, there is an additional load case for Design Pressure and Design Temperature that computes and show results for “Displacements”, “Element Forces” & “Moments”, “Support Loads” and “Support Load Summary”.

Click in the Layout window or press F3 to move the focus to the Layout window.

4. Input Model Layout

We are going to model the 8” header line ﬁrst, followed by the 6” branch line.

Note:

· In the following text, the word “type” should be distinguished from the words “Type column” or simply “Type” (upper case “T”). The former (“type”) would mean press the keys for the text you want to type. The latter word “Type” would refer to the Type column in the Layout spreadsheet.

· Also, the instruction “type B for Bend” does not necessarily mean the upper case “B”. The lower case “b” could also be typed.

· For items input in the “Data” column (such as “Anchor” or “Hanger”), the cursor needs to be in the “Data” column. This can be quickly done by pressing Ctrl+D from any column or clicking in the “Data” column. Another way is to Tab repeatedly to reach the “Data” column.

· As the graphics window is simultaneously updated, you should position the graphics window in such a way that you can see it along with the input window.

First the 8” header

Following the “Title” at row #1, row #2 is already generated with “Node” 10 of Type “From” with an “Anchor” in the “Data” column.

Press “Enter” to move the highlight to the next row #3. Tab to the “Type” column. The next “Node” 20 is automatically assigned. In the “Type” column, type “b” (for Bend), Tab to “DX”, type 9. Tab over to “Material”, type A53, Tab to “Section”, type 8, Tab to “Load”, type 1. Press “Enter” and the cursor moves to the next row (#4).

You will see the model in the graphics window as it is entered. You can press “F2” to switch between text and graphics windows.

In row #4, Tab to the “Type” column. The next “Node” 30, is automatically assigned.

In row #4 with “Node” 30, Tab to “DZ”, type 6, Tab to “Data” (or press “Ctrl+Shift+D”), type “h” (for a to be designed Hanger) and press “Enter”, the “Hanger” dialog is opened.

Press “Enter” or click on “OK” to input the hanger. The material, section and load are automatically inserted (based on the previous row’s material, section and load), and the cursor moves to the next row.

The Graphics window will look like this.

In row #5, Tab to the “Type” column. The next “Node” 40, is automatically assigned. In the “Type” column, type “b” (for “Bend”) and press Tab. This bend has a non-standard (user deﬁned) bend radius. Therefore, the bend radius needs to be modiﬁed from the default long radius. Double click on the “Bend” in the “Type” column or press “Ctrl+T” to bring up the “Bend” dialog box. Click on “User” (Bend Radius > User) radio button and enter 18 for “Bend Radius”. Press “Enter” or click on “OK” to modify the bend.

While still in row #5, Tab to “DZ”, type 6 then press- “Enter”. The material, section and load are automatically inserted like before, and the cursor moves to the next row.

In row #6, Tab to the “DY” column. The next “Node” 50, is automatically assigned. In the “DY” column, type -6, Tab to the “Data” column or press “Ctrl+Shift+D” to move to the data column, then type “a” (for “Anchor”). Anchor, material, section and load fields are automatically inserted, and the cursor moves to the next row.

Let us specify a thermal anchor movement for the “Anchor” we just put in at node 50. Double click on the “Anchor” at node 50 in row #6. The “Anchor” dialog comes up.

Note:

Option “Anchor in Pipe LCS” allows the user to input Anchor stiffnesses in the “Local Coordinate System” (LCS) of the adjoining pipe. On the other hand, if “Anchor in Pipe LCS” is not turned ON, then the user has to input Anchor stiffnesses in the “Global Coordinate System” (GCS).

Click on “Displacements” button. The “Speciﬁed Displacements” dialog for the anchor comes up. Tab to “Y” displacement ﬁeld and type 0.5.

Press “Enter” to exit the “Speciﬁed Displacements” dialog. Press “Enter” again to exit the “Anchor” dialog. In the “Layout” window, press “Enter” to move to the next row.

Click on the “Zoom All” button (or press “Ctrl+A”) to view the 8” header line fully in the graphics window.

Now the 6” branch

Let us input a comment saying that this is a 6” std pipe. On an empty row, if the ﬁrst character in the Node ﬁeld is input as “c”, that row becomes a comment row. On row #7, type “c” to create the comment and then type: “6” std pipe” and then press “Enter” to go to the next row.

On the next row (#8), type 30 for Node, Tab to the “Type” column, type “f” (for “From”, since we are beginning a new branch), press “Enter”. In the next row (#9), Tab to the “DX” column. The next “Node” 60 is automatically assigned. In the “DX” column, type 6 and press “Enter”.

CAEPIPE inserts the previous material, and automatically detects the new branch and asks if you want to change section.

Since we want to change the section to 6, click on “Yes”. This opens the “Select Section” dialog.

Select the 6” section by double clicking on it. The section (6) is entered in the “Section” column in the “Layout” window. Press “Enter” to go to the next row. The load is again automatically inserted from the previous load.

The graphics window will look like this.

In the next row (#10), Tab to the “Type” column. The next “Node” 70, is automatically assigned. In the “Type” column, type “v” (for “Valve”). This brings up the “Valve” dialog box.

In the “Valve” dialog box, type 200 for “Weight”, 50 for “Additional Weight” and 18 for “DY” offset. Then press “Enter” or click on “OK” to input the valve. The “Thickness X” and “Insulation weight X” are automatically added as 3.00 and 1.75 by CAEPIPE as shown.

In the Layout window, type 2 for “DX” offset and press “Enter”. The material, section and load are automatically inserted as before, and the cursor moves to the next row.

In the next row (#11), Tab to “DX”. The next “Node” 80 is automatically assigned. In the “DX” column, type 6. Tab to “Data” or press “Ctrl+Shift+D” to move to the data column, then type “a” (for “Anchor”). Material, section and load are automatically inserted like before, and the cursor moves to the next row.

5. Select Load Cases for Analysis

Select “Load cases (4)” from the Loads menu.

The “Load cases” dialog is shown.

By default, “Sustained” (W+P), “Empty Weight” (W), “Expansion” (T1) and “Operating” (W+P1+T1) load cases are already selected. “Design” (W+PD+TD) load case when selected for the “Analysis”, CAEPIPE will compute and show results for “Displacements”, “Element Forces & Moments”, “Support Loads” and “Support Load Summary”. A design load case does not include “Stress Calculations”, “Rotating Equipment Qualifications” and “Flange Equivalent Pressure Calculations”. Press “OK” to return to the “Layout” window. The model input is now complete.

Click on the “Zoom All” button (or press “Ctrl+A”) to show the whole model in the graphics window.

To see a 3D rendered view of the model, click on the “Render” button (or press “Ctrl+R”) in the graphics window.

To return to the non-rendered view, click on the “Do not render” button (or press “Ctrl+R”).

List

One of the useful features of CAEPIPE is the ability to show a list of all like-items such as anchors, bends etc. in a separate “List” window. Click on the “List” button (or press “Ctrl+L”) to show the list dialog.

Click on an item of interest to show the list for that item. A list of all the anchors in the sample model is shown below:

The highlighted item can be edited directly in the “List” window (in most cases) or in a dialog by pressing “Ctrl+E”. The items can be deleted by pressing “Ctrl+X”. The item is also highlighted in the graphics window by ﬂashing and with a box around the node number.

A list of all the bends in the sample model is shown below:

Editing in the Graphics Window

Another useful feature is the ability to edit an item in the graphics window. When an item such as a “Hanger” is clicked in the graphics window, a dialog box for that item is opened, where it can be modiﬁed.

Save the model by clicking on the Save button.

The “Save Model As” dialog is shown.

Type the File name as “Sample” and press Enter to save the model. We are done with modelling. Let us analyze now.

6. Analyze

Click on “Analyze” under the File menu.

After the analysis, you are asked if you want to see the results. Select “Yes”.

7. View Results

After ﬁnishing the analysis and choosing to see the results or by opening the results ﬁle (.res), the results window is displayed. The “Results” dialog is opened automatically.

Select an item of interest by clicking on it. When you are viewing the results, use Tab (or “Next Result” button) to view the next result and “Shift+Tab” (or “Previous Result” button) to view the previous result. The “Results” dialog can be brought up by clicking on the “Results” button (or press “Ctrl+R”).

While viewing the results, the model data can also be simultaneously viewed in separate “Layout” and “List” windows. These are now “read only” windows, i.e. the model data cannot be modiﬁed while viewing the results. Some of the results from the sample problem are shown below:

Sorted Stresses

The computed stresses (“sustained”, “expansion” and “occasional”) are sorted in descending order by stress ratios.

When the stress ratio exceeds 1.00, the stress and the stress ratio are shown in red. In this particular case, the high thermal stresses may be reduced by replacing the anchor at “Node” 80 by a guide. This allows the 6” pipe to expand more freely and reduce the thermal stresses. The maximum thermal stress is reduced to 22784 psi and the stress ratio is reduced to 0.77.

Color coded stresses may be rendered in the graphics window by pressing the “Show Stresses” button (or choose “View > Show Stresses”). The stresses in the highlighted columns (the bar highlights three columns simultaneously) are displayed in the graphics window. Use the left and right arrow keys to change the highlighted column or click in a particular column.

The stress ratios may similarly be rendered by using the “Show Stress Ratios” button (or choose “View > Show Stress Ratios”).

Instead of rendering color coded stresses/ratios, the values of stresses/stress ratios may be plotted by using the menu: “View > No color coding”.

While plotting stresses or stress ratios, thresholds may be speciﬁed (choose “View > Thresholds”). Only the stresses or stress ratios exceeding the thresholds are plotted.

Code compliance

The element stresses and stress ratios calculated according to the piping code are shown under “Code Compliance”. Design pressure and CAEPIPE calculated “Allowable pressures” are shown in 2^nd column.

Hanger report

The hanger report is shown below.

The “No of” ﬁeld shows the number of hangers required at the indicated location. The “Figure No.” and “Size” refer to the manufacturer’s catalog. The vertical travel (also referred to as “Hanger travel”) is the vertical deﬂection at the hanger location for the ﬁrst operating load case. Similarly, the horizontal travel is the resultant horizontal deﬂection at the hanger location for the ﬁrst operating load case. The hot load is the hanger load at the operating condition and the cold load is the hanger load at zero deﬂection.

Variability (%) = (Spring rate × Hanger travel / Hot load) × 100

Support load summary

“Support load summary” for each support is created by considering all the load cases and appropriate combinations and then showing the maximum and minimum loads.

Use the “Other supports” button (F6), “Next support” button (“Ctrl+Right arrow”) or “Previous support” button (“Ctrl+Left arrow”) to see loads on other supports (e.g. other anchors, hangers etc.).

Support loads

Support loads are the loads acting on the supports by the piping system for the selected load case. The loads on anchors for the “Sustained” case are shown below.

Use the “Load cases” button, “Next load case” button (“Right arrow”) or “Previous load case” button (“Left arrow”) to see loads for different load cases (e.g. Sustained, Expansion etc.).

Use the “Other Supports” button (F6), “Next support” button (“Ctrl+Right arrow”) or “Previous support” button (“Ctrl+Left arrow”) to see loads on other supports (e.g. other anchors, hangers etc.).

For example, the loads on hangers (i.e. the loads acting at the hanger locations imposed by the piping system) for the “Expansion” case are shown below.

Element Forces

For pipe (also bend and reducer), element forces in local coordinates, “Stress Intensiﬁcation Factors” (SIF), “Flexibility Factors” (FF) and stresses are shown by default for the selected load case.

Use the “Global Forces” button (F7) to see the element forces in global coordinates.

Use the “Local Forces” button (F7) to see the element forces in local coordinates.

Use the “Other Forces” button (F6), “Next Force” button (“Ctrl+Right arrow”) or “Previous Force” button (“Ctrl+Left arrow”) to see other element forces (e.g. valves, bellows etc.).

Displacements

The nodal displacements are shown.

Use the “Load Cases” button, “Next load case” button (Right arrow) or “Previous load case” button (Left arrow) to see displacements for different load cases (e.g. Sustained, Expansion etc.).

Use the “Deﬂected shape” button (or “View > Show deﬂected shape”) to plot the deﬂected shape in the graphics window.

Use the “Animated deﬂected shape” button (or “View > Show animated deﬂected shape”) to plot the animated deﬂected shape in the graphics window.

Choose “View > Magniﬁcation” to change the magniﬁcation of the deﬂected shape.

The reset button is used to calculate a default magniﬁcation factor which scales the maximum deﬂection to about 5% of the width of the graphics window.

Use the “Other displacements” button (F6), “Next displacement” button (“Ctrl+Right arrow”) or “Previous displacement” button (“Ctrl+Left arrow”) to see other displacements (e.g. Min/Max, displacements at hangers, ﬂex joints, limit stops etc.).

The minimum and maximum displacements for each of the directions and the corresponding nodes are shown below.

The displacements at hanger nodes are shown below.

Print

To print results and model data, click on the Print button (or press Ctrl+P). In the “Print Results” dialog, the items to print can be selected.

You can also print to a text ﬁle by using the “To File” button. A preview of the printed output can be seen by using the “Preview” button.

The printing options such as choice of printer, margins, portrait or landscape and font can be set on the Printer tab.

The sample problem report is shown next. Observe that for sorted stresses and code compliance, when the stress ratio exceeds 1.00, the stress and the stress ratio are shown in white letters on black background.

This is the end of the tutorial. If you have questions or comments, please email them to:

support@sstusa.com.