Performing failure analyses is essential to the continuous improvement of numerous industries including nuclear power plants, manufacturers, pharmaceuticals and more. When a part fails, it is important to take corrective action based on a solid understanding of why the component failed. Through Exelon PowerLabs’ failure analysis services, we identify the root cause of failure. This is an important step in to ensuring production does not experience recurrence of a similar failure, furthering delays or downtime. A transducer with a history of known failures was sent to Exelon Powerlabs for a failure analysis. Learn how Exelon PowerLabs engineers not only identified the root cause, but how this failure could have been avoided if it was Parts Quality Initiative (PQI) tested.

Determining the Cause Against the Known Failure

An I/P converter / transducer was sent in for failure analysis after the output air was not correctly controlling air pressure. Since this part is a safety-related component, it is critical a failure analysis is performed to ensure the problem is identified, and that preventative action is taken prevent recurrence. This transducer model has a known history of failure as the manufacturer provided an in-house investigative report of their own. The customer requested the part be further examined and tested against the known failure to ensure that was the only reason for the failure.

The laboratory engineers reviewed the manufacturer’s investigative report. The failure existed within the retaining pin (roll pin) responsible for holding the pressure control mechanism inside the component. The retaining pin controls the output air pressure between the I/P converter. The findings identified the roll pin was not inserted correctly, leaving the mechanism stagnant and unable to control the air pressure.

A Series of Examinations

As part of Exelon PowerLabs’ failure analysis services, a visual inspection is performed when there is documentation of any noticeable defects. For special circumstances, an x-ray will be taken to further investigate. In this case, engineers compared the lab’s x-ray to the manufacturer’s x-ray provided in the original investigative report. It was confirmed the roll pin was sticking out in both examinations and hindered output air pressure.
Engineers moved on to perform a functional test based on manufacturer’s specifications. Successfully, the failure was able to be replicated by the functional test. Further testing eliminated any possible reasons aside from the known failure previously confirmed.

Confirming the Root Cause of the Failure

Once the failure was confirmed and verified against the manufacturing defect, the customer was given a detailed report along with recommendations for corrective action from our engineers.
One option would be to design-out the part to improve equipment reliability and prevent a future failure. Another option would be to institute a screen test to act as a preventative, essentially PQI (Parts Quality Initiative) test it using Exelon PowerLabs’ proven PQI testing templates. PQI testing requires known high failure-rate components be tested before installation.

Preventative Maintenance with PQI Testing

PQI (Parts Quality Initiative) is about testing and screening defective parts before entering inventory and most importantly, installation. If this component was originally PQI tested, the manufacturing defect would have been flagged long before it would have been installed in the plant. In the PQI program, if a failure is identified, it may be quickly sent back to the manufacturer under warranty if the customer chooses and replaced at no cost.

As a result of performing pre-receipt inspections through PQI, companies prevent downtime. PQI pre-emptively identifies infant mortality while testing functionality, repeatability, leakage or other problems to ensure customers are receiving and installing quality parts.

Our failure analysis services work together with PQI testing in identifying failures. Exelon PowerLabs’ experience in failure analysis combined with decades of failure analysis data has created a successful path for our engineers to make critical decisions. When performing a failure analysis, our engineers have access to PQI performance data to help them identify key failure trends. The PQI cycle is enhanced as new failure modes discovered in failure analysis are incorporated into PQI test methods.

Reducing Failures

The manufacturing defect that found in the transducer and resulting complications could have been avoided if the transducer had been screened by PQI testing. Through the investigative and inquisitive nature of our expert failure analysis team, we were able to provide a detailed failure analysis report and recommend corrective action to reduce the likelihood of experiencing another failure.
With PQI testing as the first step of the parts readiness process, it ensures defective parts do not enter inventory or installation. If PQI testing was implemented beforehand, the part would have never reached the point of installation and would not have failed after installation. While performing a failure analysis service is necessary in identifying the root cause, PQI testing safeguards against downtime by identifying defective parts before they under-perform.