| Applies To | |||
| Product: | AutoPIPE | ||
| First Affected Version: | 09.06.00 | ||
| Found in Version: | 11.04.00.xx | ||
| Fixed and Released in Version: | 11.04.00.xx | ||
| Area: | All | ||
| Severity: | Critical | ||
| Backlog Issue Number: | 905085 |
Behavior
• Severity: 1 - Critical
• First Affected Build: 09.06.00.xx
• Affected Product: AutoPIPE
• Affected Versions: Nuclear
• Program Affected: Yes
• Program Help Affected: Yes
• Documentation Affected: No
Problem Description
For HDPE pipe nominal diameter 20, wall thickness for dimension ratio 8.3 is using wrong value 2.222 which belongs to dimension ratio 9. In such cases, stresses may not be calculated correctly, leading to unconservative results.
This error impacts ASME NC, ASME ND, ASME B31.1 and ASME B31.4 2004 and later piping codes..
Steps to Repeat
To illustrate this defect, the following scenario can be considered:
Step 1: Create a new ASME B31.1 model with “Include ASME CC N-755-1 (HDPE):” checked
Step 2: Define a new pipe identifier with following data
Pipe identifier: PIP1
Nominal Diameter: 20.00
Schedule: STD
Pipe Material: A312-TP316H
Step 3: Insert following data on Operating Pressure & Temperature dialog for point A00 as below
Pressure: 150 psi
Temperature: 140 Deg F
Step 4: Insert an anchor at A00 and a 20ft bend from A00 to A01 in x direction, using pipe ID “PIP1”
Step 5: Insert a 10ft run from point A01 to A02 in y direction, using pipe ID “PIP1”
Step 6: Insert new pipe Identifier with following data
Pipe identifier: PIP2
HDPE Material: Checked
Nominal Diameter: 20.00
Dimension Ratio: 8.3
Pipe Material: PE4710
Step 7: Insert following data on Operating Pressure & Temperature dialog for point A02 as below
Pressure: 150 psi
Temperature: 140 Deg F
Load Duration: 50yr
Step 8: Insert a flange with following data
Flange type: Adaptor
Weight: 100 lb.
Step 9: Insert a 10ft run from point A02 to A03 in y direction, using pipe ID “PIP2”
Step 10: Insert anchor at point A03 and run static analysis
Step 11: Take out the code compliance report and notice “Amb to T1{1}” stress at point A01 F+ as 731 psi
Step 12: Open pipe properties “PIP2” and change dimension ratio to “NS” and Wall thickness to 2.409, which is the correct value for dimension ratio “8.3”
Step 13: Analyze and take out the code compliance report
Notice that for point A01 F+ “Amb to T1{1}” code stress increased to 767 psi which is the correct value of stress with dimension ratio 8.3, while program is giving 731 psi because dimension ratio 8.3 is not using correct value of wall thickness.
Evaluation Criteria
The following considerations are provided to assist in your evaluation of the potential impact of this defect on the results:
Evaluate whether this defect has affected any existing models by considering the criteria below:
1. Was the model created or updated in program version 9.6.0 or later?
2. Was the selected piping code ASME NC, ASME ND, ASME B31.3 or ASME B31.4
3. Was the piping code year set to 2004 or later edition?
4. Was “Include ASME CC N-755-1 (HDPE)” from general model options checked?
5. Was there a pipe with “HDPE Material” checked from pipe properties dialog?
6. Was there a pipe having 20 as a nominal diameter and 8.3 as a dimension ratio?
A 'No' to one or more of the above criteria means that this defect does not affect the model’s results. No further consideration for this model is necessary.
Workaround
Change thickness to 2.409 inch by changing the dimension ratio to NS from pipe properties dialog of HDPE pipe.
Solution
Pipe identifier with “HDPE Material” checked, nominal diameter 20 and dimension ratio 8.3 should use 2.409 inch as wall thickness.
Additionally, to assist in the screening of the models created in previous program versions for any potential impact by this defect, the program shall automatically examine the model database after opening the model and generate a report (model name + "_905085.TXT"), listing the pipe identifiers potentially impacted by this defect. The program shall display the following confirmation message:
“HDPE Pipe cross section library for nominal diameter 20 and dimension ratio 8.3 has wrong value of thickness and may report incorrect stress results due to a previous program defect #905085. Would you like to review the evaluation report?”
The contents of the critical error report shall be like the following sample critical error report:
Defect #905085 Evaluation Report
--------------------------------
Model Name: TEST1
Model Version: 09.06.02.06
Program Version: 11.03.00.20 01
Report Filename: TEST1_D905085.TXT
--------------------------------
For ASME NC, ASME ND, ASME B31.1 and B31.4 stress calculations,
program may incorrectly use thickness values for HDPE pipe having
nominal diameter 20 and dimension ratio 8.3 due to a previous program
defect #905085. Please refer to the published defect report for more
details, mitigation conditions, and instructions. To assist in the
screening of this model for any potential impact by this defect,
program has examined the model database and has found that stress
results for nodes with pipe identifiers listed below may be incorrect
and should be re-computed using this program version.
After saving this model or running any analysis in this version or
later commercial release versions, this screening will no longer be
performed.
Pipe identifier(s) impacted:
-----------------------------------------------------
PIP2
Also See:
Critical and High issues released in v.11.04.00
Known Issues in AutoPIPE (Enhancements, defects, etc..)