| Applies To | |||
| Product: | AutoPIPE | ||
| First Affected Version: | 9.1.0 | ||
| Found in Version: | 11.00.00.22 | ||
| Fixed and Released in Version: | 11.01 | ||
| Area: | All | ||
| Severity: | Critical | ||
| Backlog Issue Number: | 702173 |
Problem Description
Material density, composition, and modulus of elasticity values at temperature for standard materials NI and GROUP-1-B provided with ASME Nuclear material libraries are inconsistent. For ASME2000 and later material libraries, the density value provided for GROUP-1-B and NI is 556.0 lb/ft^3, which is closer to density of pure Nickel and High Nickel alloys. The thermal expansion and modulus of elasticity values for GROUP-1-B and NI however belongs to groups which generally represent Ni steels or low alloy steels.
For ASME1986 and ASME1992 libraries, the modulus value for standard material NI are taken from Material Group B (representing Ni steels). The thermal expansion and density values however are taken from groups generally representing High Nickel N02200.
For AUTOASME material library, the material composition code for GROUP-1-B is set as Carbon Steel, whereas, it should be set to Low alloy steel instead.'
Using incorrect density or modulus values may result in lower stresses, leading to unconservative results.
Steps to Repeat
To illustrate this defect, the following scenario can be considered:
Step 1: Create a new ASME NB 2004 edition model with English units
Step 2: Define a new pipe identifier with the following data
Pipe identifier: PIP1
Nominal Diameter: 12.00
Schedule: STD
Pipe Material: Group-1-B
Step 3: Insert an anchor at A00 and a 10 feet run in Global X direction from A00 to A01, using pipe ID “PIP1”
Step 4: Insert a V-stop at A01, with Gap below pipe set to 0.0 in, Gap above set to 100.0 in, and friction coefficient of 0.3
Step 5: Insert another run at A01 continuing 30 feet in Global X direction from A01 to A02 using the following pipe identifier
Pipe identifier: PIP2
Nominal Diameter: 12.00
Schedule: STD
Pipe Material: CS
Step 6: Analyze the model for Gravity and Thermal
Step 7: Create a new Level A stress summary with the following definitions:
| Equation Index | Equation | Combination 1 | Combination 2 |
| 1 | Equation 9 | Gravity {1} | None |
| 2 | Equation 10 | Zero Moment Case | Thermal 1{1} |
Step 8: Take out the Forces and Moments, and Stress Summary output reports. Note that Resultant moment at A00 is 9,770 ft-lb, and Eq. 9 stress at A00 is 2,676 psi
Step 9: Double click PIP1 from Pipe Properties tab of Review Component Data grid and modify properties for PIP1 as shown below:
| Property | Existing Value | New Value |
| Pipe Material | Group-!-B | NS |
| Density | 556.0 lb/ft^3 | 489.0 lb/ft^3 |
Step 10:
Analyze the model again and take out the Forces and Moments, and Stress Summary output reports. Note that using the correct density value of 489.0 lb/ft^3 for PIP1 the Resultant moment at A00 increased to 9,853 ft-lb, and Eq. 9 stress at A00 increased to 2,698 psi.
Evaluation Criteria
The following considerations are provided to assist in your evaluation of the potential impact of this defect on the results:
1. Evaluate whether this defect has affected any existing models by considering the criteria below:
a. Was the model created or updated in program version 9.1.0 or later?
b. Was any edition of ASME NB, NC or ND piping codes being used?
c. Was the material library selected for the model ASME1986 or later?
d. Was there a pipe ID in the model with pipe material selected as NI, GROUP-1-B, or SA333-9?
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
Set the affected pipe IDs material to NS and manually enter the correct density, composition, and modulus of elasticity value on the pipe properties dialog. Also update the hot modulus value for operating and design pressure & temperature (required for ASME1986 and ASME1992 libraries, standard material NI only).
Solution
Program shall use the following properties for standard materials:
ASME1986 and ASME1992
NI
Density = 555.0 lb/ft^3 [ASME BPV Sec II, Part D, Table NF-2: Nickel and Low Carbon Nickel]
Modulus = N02200 (200) [ASME BPV Sec II, Part D, Table TM-4: N02200 (200)]
ASME2000 and later
GROUP-1-B and NI
Density = 489.0 lb/ft^3 [value within generally accepted range for carbon steel density]
AUTOASME
GROUP-1-B
Material composition = Low alloy steel
Additionally, to assist in the screening of the models created in previous program versions for any potential impact by this defect, program shall automatically examine the model database after opening the model and generate a report (model name + "_D702173.TXT"), listing the pipe IDs potentially impacted by this defect. Program shall display the following confirmation message:
“Material density, composition, and modulus of elasticity values for standard materials NI and GROUP-1-B may be incorrect due to a previous program defect #702173.
Would you like to review the evaluation report?”
The contents of the critical error report shall border on the following sample critical error report:
Defect #702173 Evaluation Report
---------------------------------
Model Name: TEST1
Model Version: 09.06.02.06
Program Version: 11.01.00.11
Report Filename: TEST1_D702173.TXT
---------------------------------
Material density, composition, and modulus of elasticity values for standard materials NI and GROUP-1-B provided with ASME Nuclear material libraries (ASME1986 or later) are incorrect due to a previous program defect #702173. 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 density and/or modulus of elasticity values for the pipe IDs listed below are incorrect. The impacted material properties for these pipe IDs have been updated. Model should be re-analyzed 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 ID(s) potentially impacted by this defect:
-----------------------------------------------
PIP1 PIP2 PIP3
Also See:
Critical and High issues released in v.11.01.00
Known Issues in AutoPIPE (Enhancements, defects, etc..)