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 design, a...nalysis, troubleshooting and fitness for service evaluation of piping. More

Restoring High Energy Piping System Performance by Reducing Friction

pipe_friction2 Damaged/Destroyed Low Friction Sliding Surfaces
"When You're Stuck, You're Stuck" Over years of normal operation - like cycling and wear and tear - High Energy Pipe support friction can increase causing distress in these critical systems. Friction is a common phenomenon which is widely understood and considered in both piping analysis and support design.  Generally, a piping analyst models a piping system with a friction coefficient on all base type supports of 0.3 for steel on steel or lower if a low friction sliding surface will be used, and hits “run” on his design software program.  The stresses are evaluated, loads on supports determined, and the analysis is off to support design.  The support designer takes the loads (which include friction) and designs the support.  No errors were made, the calculations are correct, and everything should work. But what happens in the field after years of operation and cycling? That depends on several variables, including the...
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ASME B31.3 - Substantive Changes in the 2018 Edition for Process Piping

B31-3_ASME
In addition to the many clarifications, updated references to codes and standards, updates to basic allowable stresses, and added listed materials, there are several substantive changes to the 2016 Edition of ASME B31.3, Process Piping, which is scheduled to be issued mid-January 2019. These substantive changes are: Owner Added specific permission for the owner to designate a representative to carry out selected responsibilities required by this Code, and noted that the owner retains ultimate responsibility for the actions of the representatives. Flange Design Added the ASME B&PV Code Section VIII, Division 2, para. 4.16 flange calculation method as an acceptable way to design flanges for B31.3 applications. The Division 2 procedure considers pressure, gasket seating, and externally applied axial forces and net-section bending moments. Stress Intensification and Flexibility Factors Added specific references to ASME B31J-2017 as a resource for stress intensification and flexibility factors as an alternate to Appendix D. High Cycle Fatigue...
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Basics of Design By Analysis in ASME Section VIII, Division 2

fea-pressure-vessel-nozzl_20181115-174743_1
How hard can it be?  I’ve heard from several (unnamed) analysts that because they have access to an FEA program and have successfully applied FEA in other fields, that FEA for pressure vessels should be a snap.  What is it about FEA for pressure vessels that makes it unique? I was recently discussing with another blogger regarding some distinctive aspects of performing Design By Analysis for pressure vessels.  We generated several questions, and so I decided to post this in a Question & Answer format. When do I have to use FEA in my pressure vessel design? The short answer here is that for most situations, you probably should not be using FEA to design your pressure vessel.  The rules for designing pressure vessels in ASME Section VIII, Division 1 and ASME Section VIII, Division 2 have a long history of successful application.  So, wherever possible, I would recommend that you...
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Reducing Loss of Primary Containment (LOPC's) in a Refinery

cover-LOPCs
Reducing Loss of Primary Containment (LOPC's) or commonly referred to as “leaks” in a refinery is a key factor to improve reliability.  Historically, most refiners reduced the high consequence leaks to avoid major incidents; however, lower consequence related leaks were not given high priority.  Today high reliability is required, and reduction of all leaks is desired due to greater legal and regulatory oversight of the industry.  Approximately 90% of the leaks occur in piping systems.  These leaks typically fall into 3 categories; internal corrosion, flange leaks and external corrosion.  Many refiners have programs in place for internal corrosion and programs for flanged joints; however, many lack comprehensive programs for external corrosion. To fully reduce LOPCs a comprehensive internal and external corrosion management system is necessary. Background Many refineries have had Mechanical Integrity related audits performed during the last decade.  These audits have found many areas for improvements and programs were initiated...
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