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Here are some examples of how System Engineering could have affected an FAC Program:
- Modified a piping arrangement so that it has a direct impact on FAC and the FAC Engineer was not “in the loop” to provide proper input, i.e. use of FAC resistant material, an increased pipe size to reduce flow velocity or relocation of in-line component.
- Replaced a valve that was having problems, but never informed the FAC Engineer of the valve problem.
- Also, if the FAC Engineer was not informed that the valve was cut out and removed, the change also did not allow for an “inspection of opportunity” to visually inspect the line or the old valve.
Design Engineering
Design Engineering has the responsibility to qualify the piping system for the proposed plant modification, originate the appropriate modification package and develop minimum acceptable wall thickness values.
Here are some examples of how Design Engineering could have affected an FAC Program:
- Were unable to develop
and provide the FAC Engineer with the minimum acceptable wall thickness value.Advertisement - Generated a piping modification without including the FAC Engineer as part of the review process.
Plant Documentation
Plant Documentation is responsible for having on record all plant drawings and reports, as well as updated drawings that are necessary for the FAC Engineer to utilize.
Here are some examples of how Plant Documentation could have affected an FAC Program:
- Did not have the most up to date drawings that reflect the piping configuration out in the plant.
Non-Destructive Examination
Non-Destructive Examination is responsible for performing the inspection of the FAC piping component or equipment and reporting the results to the FAC Engineer.
Here are some examples of how Non-Destructive Examination could have affected an FAC Program:
- The FAC component’s minimum measured thickness or the maximum measured thickness was not verified.
- No scan was performed of the localized region where the minimum measured thickness was recorded to verify that it was the lowest reading in the region.
- The incorrect component was gridded and examined.
- The grid layout was incorrectly applied to the component with respect to the direction of flow or the gridding procedure. An example of correctly applied grid profile is shown in Figure 1.
Figure 1 displays the row and column lines marked on the components by NDE personnel for an inspection location to be examined by Ultrasonic Testing (UT). The row numbers increase in value longitudinally along the location with the direction of flow. The lettering of the column lines are applied circumferentially around the pipe in the clockwise direction following the “right hand rule” with respect to the direction of flow.
FAC Engineer
The FAC Engineer is responsible for interfacing and communicating with all the disciplines mentioned earlier to gather the necessary information to make an informed decision on what examinations need to be performed and when, or to defer an exam to a later examination period.
The FAC Engineer also has to determine if the inspected component can remain in service, or if it should be replaced. They also should issue an Outage Summary Report.
In addition, the FAC Engineer should regularly review the following reports: system status reports, condition reports, operator’s log, thermography results, incident reports, work orders, etc.
The FAC Engineer also should attend industry conferences.
Training
The FAC Engineer should provide a series of training sessions with individuals from the various departments to educate the individuals about flow accelerated corrosion – what is FAC, where it can occur, what goes into selecting an inspection location and how each group has specific information necessary for the FAC Engineer to use to develop the plant’s inspection plan.
Conclusion
It was asked earlier which group is responsible to minimize a FAC component from failing at their facility that could bring the unit down or cause injury to plant personnel. If a failure does occur, the burden falls solely with the FAC Engineer.
