| Applies To | |
| Product(s): | AutoPIPE |
| Version(s): | ALL; |
| Area: | Modeling |
| Date Logged & Current Version | Jan 2023 12.08.04.009 |
Problem:
How to test if a branch pipe is actually connected to a header pipe while using AutoPIPE?
Which of the following Tees is connected and which is not?
Solution:
There are a number of ways to know if a tee / pipe are connected:
a. Using the Keyboard arrows
b. Coincident Node report
c. Node point labels
d. Review Input grids (tee tab, Segment Tab, Points Tab)
e. Connected Segments
f. Model Consistency check report
g. Animate load case(s)
h. Graphics: Tee arrows
Using the Keyboard arrows:
Place the active point at any node point,. Next using the keyboard arrows navigate through the model
Therefore, move the active point to the intersection of a tee and press the Up arrow key or Down arrow key to change segments. Notice the lower right corner of the application screen to see the active node point name remain the same but the active Segment name should change.
Example, place active node point at A01 and press the keyboard Up arrow key or Down arrow key, what happens to the active segment name?
If nothing changes when pressing the Up / down arrows, then there is only 1 segment connected to the current node point.
If segment name changes when pressing the Up / down arrows, then there are only 2 segments connected to the current node point.
Coincident Node report:
Run Coincident Node Check command. The report will be generated for the user to clearly see what node points are within the tolerance distance. Increase / decrease the tolerance distance as needed.
Clearly, node points C01 from segment C and D00 from segment D are directly atop one another; thus are not connected.
See AutoPIPE hep for more information on this feature.
Node point labels:
Change to single line graphics mode and zoom into a suspected tee node point.
Notice that a connected tee has only 1 node point label, where a tee that is not connected has 2 node point labels.
Review Input grids (tee tab, Segment Tab, Points Tab):
Tee tab
Open the tee tab of the input grids, only connected tees are placed on the grid, if a suspected too is not listed here then it is not connected correctly.
Since there is not tee listed with Point name on segments C or D, therefore there is no tee. Check the segment connectivity.
Segment tab
Select the Segment Tab of the input grids, compare the First Point and Last Point names to that of the segment name.
Does the node point names have the same letter as the segment
If YES, typically the segment starts and ends without being connected to another segment
If NO, typically the segment is or was connected to another segment.
Clearly in this case, since segment B started at A01, it is most likely connected to segment A. However, segment D started at D00, which typically would indicate that it is not connected at all to segment C.
Points tab
On the Points tab of the input grids, the same holds true as seen on the Segment tab above. Take note of the point name just to the right of Origin, this will be the first node point in a segment. The last node point of a segment would occur on the line just above the next occurrence of Origin listed below.
Does all of the node points of a segment share the same letter?
If YES, typically the segment starts and ends without being connected to another segment
If NO, typically the segment is or was connected to another segment.
Clearly not all of the node points on Segment B share the same letter. thus it is likely connected or was connected to a different segment.
However, segments C and D node points share the same letter, thus likely these segment are not connected to other segments.
Connected Segments:
From the Select ribbon, run the Connected Segments command.
This clearly shows which segments are connected and which are not connected.
Beware, this is not a true picture if all of the segment in a group are correctly connected at each junction. This is just a quick check to see if a model has multiple groups.
In this example, it clearly indicated that Segments in Group 1 are connected somehow, where the segments in Groups 2 and 3 are not connected at all.
Model Consistency check report:
On the analysis ribbon, run the Mode Consistency check command.
One or more warning may indicate problems with connected segments.
Example:
* * * W A R N I N G - MODEL * * *
W726-12: Following Segment(s) not connected to other segments and has no anchors
D
* * * W A R N I N G - MODEL * * *
W726-170: The tee at following point(s) has only two legs defined which may not meet
the conditions to apply the equations for SIF and other stress indices.
C01
As indicated here in this example, there is an issue with Segment D and node point C01 that requires further investigation.
Animate load case:
This makes the issue bluntly obvious that a tee is not connected.
Use the Displacement (Result > Interactive > Displacement) command to animate one or all load cases.
Note: select from the bottom right corner of the video to enlarge to full screen mode.
Graphics: Tee arrows
As a quick visual check, AutoPIPE has a feature that graphically shows a Tee's arrows. These arrows can be turned On/Off on the Settings dialog (View > Setup > Settings).
With the Show Tee Arrows turned on, one can clearly see some blue arrows representing the legs of a tee. When the arrows are inline with each of the 3 directions of a standard Tee, typically the tee is connected. Verses when one of the blue arrows is not inline with a pipe, which typically indicated a tee with only 2 legs (see consistency check message above).
***Warning***
1. Just be cause the blue arrows are overtop the pipe does not mean the tee is 100% positively connected. If a pipe segment just happens to be in the same direction as the arrow, it could give the false impression that the tee is connected when it actually is not connected. Again, this is a quick visual check, therefore use one of the other techniques above to confirm 100% if the tee is connected or not.
* * * W A R N I N G - MODEL * * *
W726-170: The tee at following point(s) has only two legs defined which may not meet
the conditions to apply the equations for SIF and other stress indices.
A05
2. There is a known graphical issue with the Blue arrows where they may not show. At this point try changing the graphics from solid model to single line mode and back again to solid model. This will be fixed in a future version of the software.
See Also
Correct a incorrectly modeled Tee
Tee, Cross, or Branch Piping Components - Modeling Approaches