Applies To
	Product:	AutoPIPE
	First Affected Version:	09.01.00.xx
	Found in Version:	10.00.00.10
	Fixed and Released in Version:	11.00.x
	Area:	Combination
	Severity:	Critical
	Backlog Issue Number:	619540

Problem Description

Stress indices and stress results for negative face of a reducer near node that is directly connected to a tee branch may be reported incorrectly. The stress results for the negative face of near end of such reducers in both pre-verification and stress summary reports may be impacted. Reports may display “NaN”, short for Not a Number, in the generated output. The reported stress values may be lower than the actual stress values, leading to unconservative results.

Steps to Repeat

To illustrate this defect, the following scenario can be considered:

Step 1: Launch a fresh instance of AutoPIPE and create a new ASME NB 2004 edition model with English units

Step 2: Define a new pipe identifier with the following data:
Pipe Identifier: PIP12
Nominal Diameter: 12.000
Schedule: STD
Pipe Material: SA106-B

Step 3: Insert an anchor at the first point A00 in the model

Step 4: Insert a welding tee at A01 with header connected to the anchor at A00

Step 5: Extend the header in the direction of the pipe by inserting a run from the tee point A01 to A02

Step 6: Place a branch pipe from A01 to B01 perpendicular to the header using the following pipe properties:
Pipe Identifier: PIP08
Nominal Diameter: 8.000
Schedule: STD
Pipe Material: SA106-B

Step 7: Insert a reducer from point B01 to B02 using the pipe Identifier PIP12 for the far end of the reducer

Step 8: Insert a run from the reducer far point B02 to B03

Step 9: Analyze the model

Step 10: Create a new Level A stress summary with Gravity load for Equation 9, and Zero moment case and Thermal 1{1} for equation 10

Step 11: Take out the stress indices, preliminary stress, and stress summary reports for the model

Depending on the program version being used and piping code edition, you may see NaN reported under preliminary stress report, zero stress values reported under stress summary report, and/or NaN under stress indices report for the negative face of reducer near point B01.

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 the Piping code for model set to ASME NB “1972 + 1972 W addenda” or later edition?
c. Was there a reducer near point in the model connected directly to a tee branch?

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.
Otherwise the following mitigation conditions may apply:

1. None

Solution

Program should set the negative face of near point of a reducer as a run point. The stress indices and stress calculations should consider the negative face of near point of a reducer connected directly to branch of a tee as a run point.

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 + "_D619540.TXT"). The program shall display the following confirmation message:

“Stress indices and stress values for a reducer minus face connected directly to a tee branch may be calculated incorrectly due to a previous program defect #619540. Would you like to review the evaluation report?”

The contents of the critical error report shall be similar to the following sample critical error report:

Defect #619540 Evaluation Report
---------------------------------

Model Name: TEST1
Model Version: 09.06.02.06
Program Version: 11.00.00.13
Report Filename: TEST1_D619540.TXT

---------------------------------

Stress indices and calculated stress results for negative face of a reducer near node that is directly connected to a tee branch have been revised in this program version to correct defect #619540. 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 the stress indices and calculated stress values at the nodes listed below 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.

Reducer point(s) potentially impacted by this defect:
-----------------------------------------------------

B01 -

Also See:

Critical and High issues released in AutoPIPE CONNECT v.11.0