Boiler & Pressure Vessel Code, Rules for Construction of Nuclear Power Plant Components Division 1, Subsection ND, Class 3 Components Applies To Product(s): AutoPIPE, Version(s): 2004, XM, & V8i Environment: N/A Area: piping code Subarea: Original Author: Bentley Technical Support Group Comments, Questions, and Answers on ASME ND Piping code in AutoPIPE #1. Question: For a system for which level C service conditions are specified in the Design Specification, ASME Section III Subsection ND requires "the conditions of eqs. ND-3653.1 (a)(9a) and ND-3653.1(b)(9b) shall be met using Service Level C coincident pressure P and moment (MA + MB), which result in the maximum calculated stress. AutoPIPE appears to use the "Peak Pressure" when performing this calculation. If the Service Level C coincident pressure P differs from the Peak Pressure (Level A and B), how can the Level C pressure be specified for this calculation? Answer : AutoPIPE conservatively used peak pressure as it isn't able to identify the load case to get the coincident pressure from. Reprocess the results manually to check the affect of this. #2. Question: How to find out what SIF does AutoPIPE use for stress calculations in each point, for example in tees using ASME ND 1992+1993 addenda? Answer : See AutoPIPE output report Stress Indices. #3. Question: I have a question regarding ND equation 10 code stress combination for thermal case . Autopipe combines zero moment case. I could not get more detail or explanation of zero moment case from Autopipe work book. Can you please explain what is zero moment case and which code clause states this requirement to be included in the stress calculation? Answer: For Equation 10 in the Stress Summary dialog, the zero option indicates the inclusion of a zero moment option corresponding to zero pressure, zero moment and room temperature. It represents the cold condition (i.e. the starting point for stress ranging). It is included for convenience where a specific cold condition load case has not been created. #4. Question: Where should then Non-repeated Anchor Movement (e.g. Building Settlement) be accounted for if not in Equation 10a as the ASME ND says? Are the values under EQ.10a in Stress Summary Output always zero? Answer: Insert an imposed support displacement on a user case. Go to code combinations, and create a new combination by filling the fields as shown below: Combination method = Sum Category: Non-repeated Support Movement You would be able to see the results for that combination under pre-verification stress report. You shall also be able to define user allowable for eq. 10b as is the case with all other equations. Furthermore, we are printing Equation 10a and 11a in the report for pre-verification only. Note: ADLPIPE did not have 10a (Supp Move category) in the stress summary. Below is the section in the online help which highlights this 10a now 10b limitation Help Contents Contents Tab Reference Information ASME BPV-III-1-ND Level A and B Service Limits Code Compliance Calculations ND - Single Non-Repeated Support Movement (Equation 10a). A new enhancement has been logged, TFS-74287 #5. Question: Could you please provide an example, how to define building settlement and where to put it in Stress Summary? Answer: Example for inserting Building Settlement for pre-verification stress report is mentioned above. For stress summary report, this option is not yet available. An enhancement has been logged to be able to account for that in the future releases. Currently it seems that the results for equation 10a(10b for 2007 and later) would be reported as zero. #6. Question: Why does the calculated allowable = 29802 psi for "ASME ND (2007) PRE-VERIFICATION STRESS REPORT", Eq 8, Load case = GR, not match the hand calculated value of 30000 psi Note: hand calculated value = 1.5 x Sh = 1.5 x 20000 psi (from Press/Temp/PipeID tab of the input grid) = 30000 psi. Answer: Open the model. Please see the following AutoPIPE help section: Help Contents Contents Tab Reference Information Code Compliance Calculations ASME BPV-III-1-ND (1972 - 2007) Design Condition Now find the indicated node point (ex. 130) on the "Design Press / Temp" Tab of the input grids, as shown below: Sh = 19868 psi. Allowable = 1.5 x Sh = 1.5 x 19868 psi = 29802 ps i (Matches Output report above) See Also Bentley AutoPIPE External Links Bentley Technical Support KnowledgeBase Bentley LEARN Server Comments or Corrections? Bentley's Technical Support Group requests that you please submit any comments you have on this Wiki article to the "Comments" area below. THANK YOU!
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