April's One Page Tip explores inspecting the Primary Element of fuel flow measurement systems.
Regulatory references: In Part 75, Appendix D, § 18.104.22.168. P75 Policy Manual Section 23 (Appendix D), and StackVision User Guide.
Primary elements are the components of the fuel flow measurement system which create very specific differential pressure patterns (or other technology-specific responses) as the fluid they are monitoring flows around them. Examples of primary elements include orifice plates and vortex shedding bars. Any changes to the primary element itself can cause a shift in the accuracy of the flow measurement system.
These primary elements are actual immersed in the fluid flow pipe. These fluids can sometimes be corrosive, toxic, abrasive or contain particulates which might damage or distort the shape or profile of the element. This inspection is intended to find or identify damage or corrosion to these devices. Damage or corrosion will cause these systems to operate in a manner that is unacceptable (they are now creating non-characteristic differential pressure or response patterns that do not represent the true flow rate conditions).
Documenting your findings during these infrequent inspections is not only required but important to identify trends affecting the performance of these systems.
Review the features for documenting and reporting your inspections using the “Miscellaneous Test” module found in the StackVision User Guide from the “Help” area of the StackVision software.
To perform this inspection, prepare in the follow ways:
Find and review the procedure that your facility has prepared to perform these inspections and follow it. Make sure you know what a “normal” element looks like.
A visual inspection of the metering system’s primary element is to be performed and passed within every twelve (12) calendar quarters. Under certain conditions, P75 also allows this deadline to be extended to twenty (20) calendar quarters. If you can extend the deadline, be sure you document the reason you are taking the extension.
Document the time, date, and what you observed in this inspection. Using a baroscope (a camera mounted on a gooseneck extension) is acceptable. Taking photographs of what you see is a very good idea. All documentation must be retained on-site for a period of not less than 5 years (> 60 months).
If you replace the primary element, you are required to follow up with a calibration check on the fluid flow metering system. For more information, read my One Page Tip for fuel flow metering accuracy checks.
Be sure to keep maintenance records documenting what activities were performed in association with these accuracy tests. Taking pictures of the “as found” and “as left” condition of the primary element is a good idea for documenting your work.
A primary element inspection needs to be documented in a “Miscellaneous Tests” record created in StackVision. This record is part of the QA Electronic Data Report (EDR) file and is evaluated and processed until it is error free in ECMPS before its submitted to the Environmental Protection Agency (EPA).
In StackVision, you need to prepare test record for the element inspection which was performed. Follow these steps:
Click on Tools > QA and Certification > Fuel Systems to open the Element Inspection Tab.
Click the Flowmeter Accuracy or Transmitter Transducer tab.
Click on the Add icon ( ) to launch Wizard for Creating Fuel Flowmeter Accuracy or Transmitter Transducer Tests. For details on using this Wizard, see the StackVision User Guide related to this topic.
Do you need to update your primary element inspection procedure? Are there any lessons learned or better steps to follow that you uncovered during this round of testing? Update them now to improve your chances for success next time.
For questions, suggestions, or for a general chat, please do not hesitate to contact me.
Jon Konings, Senior Regulatory and Reporting Engineer, ESC
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