Becht Engineering Blog

In this section of the site contributing authors submit interesting articles relating to the various services, industries and research & development efforts of Becht Engineering.

Becht Engineering staff are experts in piping, and include former chairman of various ASME piping committees, including ASME B31.3. Becht Engineering performs detailed design for complex piping systems including very high temperature and pressure systems such as piping for FCC flue gas expanders and high pressure LDPE systems, as well as...

Becht Engineering staff are experts in piping, and include former chairman of various ASME piping committees, including ASME B31.3. Becht Engineering performs detailed design for complex piping systems including very high temperature and pressure systems such as piping for FCC flue gas expanders and high pressure LDPE systems, as well as design, analysis, troubleshooting and fitness for service evaluation of piping.

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When Should the Rules for Severe Cyclic Conditions (Service) in ASME B31.3 Be Used?

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This posting (November 2019) is an update to an October 2013 post which reflects changes to the ASME B31.3 Code relative to severe cyclic service that have occurred since the original post. There has been a fair amount of confusion as to when the rules for severe cyclic conditions in ASME B31.3 should be used, and the rules themselves can be somewhat confusing to apply. In the 2016 edition of ASME B31.3 the definition of when the rules for severe cyclic service are applicable were changed, which may reduce the confusion.  The definition as to when the rules of severe cyclic apply is in the 300.2, Definitions.  Prior to the 2016 edition, it stated that severe cyclic conditions are: Conditions applying to specific piping components or joints in which SE computed in accordance with para. 319.4.4 exceeds 0.8SA (as defined in para. 302.3.5); and The equivalent number of cycles (N in...
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Guest — Hafiz Ali Alvi

Impact on Wall thickness for C...

Dear Mr. Becht, I would like to ask what could be possible impact of cyclic service for the calculated pipe wall thickness under p... Read More
Saturday, 16 November 2019 23:59
Chuck Becht

Impact on Wall thickness for C...

Designation of a system as being in severe cyclic service does not impact the wall thickness calculations for pressure design. No... Read More
Sunday, 17 November 2019 07:40
Guest — MK

SE calculation

Dear Mr.Becht, My understanding is that the calculation of SE (for comparing to 0.8SA in the evaluation) should include only the d... Read More
Thursday, 08 August 2019 02:03
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Operability And Fitness-for-Service (FFS) Of ASME Equipment In Nuclear Power Plants

nuclear_plant
Bringing Order and Logic to the Evaluation Process There is a multitude of documents and reports that describe the damage mechanisms of ASME pressure equipment (vessels, pumps, valves, piping, and tanks, and their supports) in nuclear power plants. Thousands of pages published by EPRI, the NRC, ASME, NACE, research laboratories, utilities, contractors, and others, to read, study, and understand. The plant engineer must understand these thousands of pages of damage mechanisms, first to take the right preventive measures, and second, when the damage occurs despite our best efforts, to correctly diagnose the remaining life of the equipment, i.e. determine its fitness-for-service, its operability. In December 2018, EPRI published “Roadmap to Integrity Evaluation and Repair of Nuclear Plant Piping” EPRI report number 3002013156, to help the plant engineer navigate through the technical and regulatory complexities of damage mechanisms and the methods for the evaluation of remaining life. This is an important step...
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CFD Modeling of a Mixing Tee – Part 1: Model Validation

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by Dave Dewees, Zumao Chen and L. Magnus Gustafsson This 2-part blog deals with CFD modeling of a mixing tee that is often found in industry. Traditional simulation is validated against experiment, as well as a new commercially available method that offers the possibility of substantial solution time reduction.  In fact, the new method is shown to give accurate results in a much shorter computer time than the traditional analysis, allowing much more rapid turnaround of difficult problems such as the turbulent mixing behavior of industrial mixing tees. When there is a large temperature difference between two fluid streams, large temperature fluctuations can occur, which can lead to thermal fatigue of the piping system, even at “steady-state” bulk flow conditions. Advanced CFD modeling is capable of predicting these fluid temperature fluctuations at the mix point, as well as characterizing the corresponding temperature variations in the pipe wall itself. Specifically, large eddy simulation...
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Guest — Prashanth Nednur

Experiment Data

Hi Dave, Is it possible to get the experimental data for this particular case ?
Thursday, 05 September 2019 17:34
Randy Ruschak

Experiment Data from Becht Blo...

Hi Prashanth, I have emailed the Excel spreadsheet data to you. thanks, Randy
Saturday, 07 September 2019 10:52
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CFD Modeling of a Mixing Tee – Part 2: Predictions of Temperature Fluctuations

cfd-mixing-T-cover
by Dave Dewees, Zumao Chen and L. Magnus Gustafsson Miss Part 1? Click Here This is the second part of a 2-part blog.  In Part 1, the stress-blended eddy simulation (SBES) and large eddy simulation (LES) approaches for simulating turbulence have been validated against test data obtained from a mixing tee. In this part, the SBES approach is used to predict temperature fluctuations in a mixing tee where light gas oil mixes with a recycled gas.  Depending on the characteristics of the streams being mixed (momentum and temperature), protection from rapid temperature variations occurring even at steady-state bulk flow conditions is a necessity. While a CFD model can predict these temperature variations with good fidelity as shown in Part 1 of this blog, once a problem is found, the same CFD model can also be used to design solutions that protect the piping at the mix point.  Here thermal sleeve length...
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