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 has extensive experience and expertise in the field of Fitness-For-Service.  We have performed evaluations for all of the damage mechanisms covered in ASME FFS-1/API 579 for clients around the world.  We have performed Fitness-For-Service evaluations on piping, pressure vessels, heat exchangers and tanks.

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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Why do Clamped Connections With Metallic Seals Sometimes Leak?

cover-pipe-clamp
Clamp connections with metallic seals can offer superior joint integrity over traditional flanged connections but caution must be exercised regarding the service conditions, especially when cyclic thermal loading is present. This blog post highlights aspects of a clamp connection analysis performed by Becht Engineering. The client had observed significant loss of bolt preload at several clamp connections installed in a refinery process unit where the fluid temperature regularly fluctuated by 700 o F. The client attempted to counteract the bolt preload loss by re-torqueing any bolts that showed a torque reduction from the initially applied torque only to find that, after a period during which thermal cycles occurred, the preload was again reduced. A typical clamp arrangement is seen in Figure 1 (with parts labeled). After reviewing the installation and service conditions, it was hypothesized that the cause of the bolt preload loss could be the differential thermal growth of the...
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Recent Comments
Magnus Gustafsson

Re: Belleville Springs

Fran, No, we did not look at Belleville washers as part of this work. I do expect they would help, but I understand the preferred... Read More
Thursday, 04 April 2019 14:18
Guest — FRAN PUGLIESE

Belleville Springs

Magnus, Did you happen to run any test using Belleville spring flange washers on the bolts? They have been used for many years on... Read More
Thursday, 04 April 2019 13:47
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Do I Have to Replace My Bulged Pressure Vessel?

Figure1-Bulged_Shape_of_Vessel-cover Need to replace bulged pressure vessel?
There are a variety of conditions an in-service component (e.g. vessel, tank, piping) can be found in.  The purpose of Fitness-for-Service (FFS) is to evaluate the integrity of an in-service component given a certain degraded condition and rate it for future service considering potential for any additional degradation.  A degraded condition does not have to just be based on corrosion. Sometimes a component can experience a large deformation due to unexpected one-time loads resulting in stresses greater than yield.  When such a large deformation event occurs it is important to inspect the vessel to make sure no cracking occurred during the deformation event.  If it is found that the impacted area is defect-free then the next step is to determine if the component can operate in the deformed shape. One example of a non-corrosion related degraded condition is a bulged tank.  Figure 1 shows an example of a tank that bulged...
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Recent Comments
Guest — Tubalcain

Insurer Issues, Liability Issu...

Continued use of a vessel not of original design may need to be accepted by the Insurer that may then pose limitations on insuranc... Read More
Friday, 12 April 2019 09:48
Guest — CS

Canadian Approach

You wrote " CSA B51 does not impose any additional design requirements for Div 1 construction, it simply defines what needs to be ... Read More
Thursday, 11 April 2019 22:48
Guest — Cameron

Degredation resulting in an al...

The line between where 'degradation' ends and alteration begins seems undefined and it seems that mandated safety requirements dif... Read More
Thursday, 11 April 2019 19:03
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Fitness-For-Service API 579-1/ASME FFS-1: Substantive Changes to the 2016 Edition

Fitness-For-Service API 579-1/ASME FFS-1: Substantive Changes to the 2016 Edition
Contributing Authors: Eileen Chant, Greg Epremian, Ranjan Nadarajah, Mark Stonehouse  Summarized herein are the substantial changes to API 579-1/ASME FFS-1, Fitness for Service , that were incorporated in the 2016 edition, as reviewed by Becht Fitness for Service experts. API 579-1/ASME FFS-1 is a Standard jointly published by API and ASME.  The purpose of the document is to provide a consensus of methods to quantitatively evaluate commonly observed damage to in-service pressure equipment.  Since it was first issued by API in 2000, this Fitness-For-Service standard has been used worldwide as a means of evaluating whether pressure equipment was fit for continued service, and in many cases, for how long.  This standard has been used to avoid costly and unnecessary unplanned outages, while maintaining safe and reliable equipment.  The Second Edition was released in 2007, followed by the most current release of the document in June of 2016.  In addition to the...
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