	Applies To
	Product:	AutoPIPE
	First Affected Version:	9.3.0
	Found in Version:	10.01.00
	Fixed and Released in Version:	11.01
	Area:	All
	Severity:	Critical
	Backlog Issue Number:	656782

Problem Description

While defining a new pipe identifier through component placement dialog, the fatigue curve for preceding point’s pipe identifier may get updated to the same as new pipe identifier or reset to blank. Subsequently, modifying the fatigue curve for any of the pipe identifiers may update the fatigue curve for the other pipe identifier as well. Due to this incorrect modification, the reported Usage factor values may be lower than expected values, leading to unconservative results.

Steps to Repeat

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

Step 1: Create a new ASME NB model with AUTOPIPE units selected

Step 2: Define a new pipe identifier with the following data:

Pipe Identifier: A
Nominal Diameter: 12.000 in
Schedule: STD
Pipe Material: SA312-TP304
Fatigue curve: ASME III I-9.2 CURVE C AUSTENETIC STEEL

Step 3: Insert the following data on Operating Pressure & Temperature dialog for point A00:

Pressure: 50 psi
Temperature: 150 Deg F
Delta T1: 50 Deg F
Delta T2: 100 Deg F

Step 4: Use the Operating Pressure & Temperature values for Design as well

Step 5: Insert an anchor at the first point A00 in the model

Step 6: Insert a pipe run of 10 ft. in X-direction, connecting point A00 to A01 with pipe identifier selected as A

Step 7: Insert another pipe run with following data

Point Name: A02
Length: 10 ft. in X-direction
Pipe data identifier: B

On clicking OK, Pipe properties dialog will appear. Change the following pipe properties

Nominal Diameter: 12.000 in
Schedule: STD
Pipe Material: SA106-A
Fatigue curve: ASME III I-9.1 80 KSI CARBON STEEL
Navigate to Pipe Properties tab of Review Component Data grid. Notice that for pipe identifier A the fatigue curve is incorrectly updated to ASME III I-9.1 80 KSI CARBON STEEL from ASME III I-9.2 CURVE C AUSTENETIC STEEL.

Step 8: Analyze the model and define a new stress summary with default selections except the following for Equation No. 10:

No. of Cycles: 2000
Combination 1: Zero Moment Case
Combination 2: Thermal 1{1}

Step 9: Generate stress summary report and notice that Usage factor for point A02 is 0.0117

Step 10: Change Fatigue curve for pipe identifier A to ASME III I-9.2 CURVE C AUSTENETIC STEEL. Re-analyze the model and generate stress summary report.

Note that the Usage factor for point A02 has changed to 0.0003 from 0.0017 when fatigue curve was only changed for pipe identifier A. This decrease in Usage factor leads to un-conservative results.

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 9.3.0 or later?
b. Was the Piping code for the model set to any edition of ASME NB?
c. Was there more than one fatigue curve selected for the pipe identifiers selected in the model?
d. Was there any node in the model connecting two pipe identifiers with different fatigue curves?

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 fatigue curve for all the linked pipe identifiers to “ASME III – ADLPIPE (Default)” and then select the required fatigue curve for individual pipe identifiers

Solution

Program should store the fatigue curve data of each pipe identifier separately.
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 + "_D656782.TXT"). The program shall display the following confirmation message:
Usage factor values for points having different pipe identifiers with same or blank fatigue curves may be reported incorrectly due to a previous program defect #656782. 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 #656782 Evaluation Report
---------------------------------
Model Name: TEST1
Model Version: 09.06.02.06
Program Version: 11.01.00.01
Report Filename: TEST1_D656782.TXT
---------------------------------
Usage factor values for points having different pipe identifiers with same or blank fatigue curves may be reported incorrectly due to a previous program defect #656782. 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 usage factor values for points with the following pipe identifiers assigned may be incorrect. Please review and update the fatigue curve for the pipe identifiers listed below with applicable fatigue curve.
After saving this model or running any analysis in this version or later commercial release versions, this screening will no longer be performed.
Following Pipe Identifier(s) may be potentially impacted by this defect.
PipeId Material Fatigue Curve
-------- ------------ -------------------------------------------------
4-STD SA335-P21
6-STD SA312-TP304 ASME III I-9.2 CURVE C AUSTENITIC STAINLESS
6-STD_2 SA335-P21 ASME III I-9.2 CURVE C AUSTENITIC STAINLESS

Also See:

Critical and High issues released in v.11.01.00

Known Issues in AutoPIPE (Enhancements, defects, etc..)