Peer Review

Questioning And Verifying Previously Submitted Ultrasonic Testing Data And Reported Opinions

A wide range of services are available in the field of ultrasonic pipe testing; with widely varying levels of quality and competence provided.  We have an entire file folder of ultrasonic testing reports, submitted to us for peer review, that would make any 5th grade teacher cringe in horror.  Worthless spreadsheets of inaccurate wall thickness data, wall thickness values without any reference to where they were taken or at what size piping, calibration to the wrong material standard, thickness measurements to 2 decimal places, childish hand drawings of pipe and mechanical layouts, wall thickness measurements not even within the realm of possibility, and even hand written reports on unlined paper.

Only worse than the work quality itself, and the lack of pride and professionalism to those responsible for such submissions, is the fact that such poor quality work is accepted by their clients.  Clients expecting to make major and potentially multi million dollar decisions upon that information.

Inaccurate And Worthless

There are many different field testing procedures and reporting methods available which will provide varying levels of diagnostic information.  In some investigations, only a limited amount of information may be required.  However, we consider it grossly unfair and unethical to produce work of little to no value, or even worse – utterly inaccurate.  In many of the UT test reports submitted to us for review, the information was not only worthless on its face value, but often led a client in the wrong direction – thereby probagating the corrosion problem.

Just Four Of Far Too Many Examples

articles peerrev 01

Unprofessional

This Stonehenge resembling submission, one of approximately 10 hand sketches, was intended to establish the condition of a highly critical data center condenser water system.  No pipe sizes are given, nor test locations, nor pipe schedules, operating conditions, or site references whatsoever.

One single wall thickness value is presented for different areas having virtually no statistical value, and supposedly defining the condition of pipe which cannot even be identified.

No useful information could be derived from this ultrasonic report.  The report was tossed out and a new investigation performed.

The above work was submitted by a Level III technician and teaching instructor for UT certification.

articles peerrev 02

Inaccurate

Another example of poor quality work, with many reported wall thickness measurements far above the realm of possibility.  The presentation of wall thickness to two decimal places, defines a more crude and low cost instrument, as well as a misunderstanding to the word “accuracy.”

A notation on the report that the surface rust present can “affect accurate readings,” by definition means that rust was not removed – thereby guaranteeing a measurement error.  Thickness measurements of 0.570 in. for standard grade pipe having a new wall thickness 0.375 in. invalidates the report on face value.  Even extra heavy pipe having an initial wall thickness of 0.500 in. would not produce such readings.

After 8 hours of work where just 12 small sections of pipe were measured, results were totally worthless.


articles peerrev 01

Unprofessional

This Stonehenge resembling submission, one of approximately 10 hand sketches, was intended to establish the condition of a highly critical data center condenser water system.  No pipe sizes are given, nor test locations, nor pipe schedules, operating conditions, or site references whatsoever.

One single wall thickness value is presented for different areas having virtually no statistical value, and supposedly defining the condition of pipe which cannot even be identified.

No useful information could be derived from this ultrasonic report.  The report was tossed out and a new investigation performed.

The above work was submitted by a Level III technician and teaching instructor for UT certification.

articles peerrev 04

Inaccurate, Too Few, And Worthless

This hand written UT test report clearly defines the number of miles the technician drove from home to the job site, but no information whatsoever regarding the pipe tested. Thickness measurements are very likely inaccurate, with almost 3 times greater wall thickness on one side of the pipe to the other.

Conversion from decinal to fractions are provided – a worthless waste of time.

In total, only 21 individual wall thickness measurements were taken over a full 8 hour day, with those measurements clearly in error.

Requirements Of A Useful UT Evaluation

In fact, producing an accurate and useful final report involves far more than just placing a UT probe to the pipe surface.  Influences include:

  1. Instrumentation used
  2. Operator training
  3. Operator experience with the instrumentation
  4. Years of experience in the field
  5. Dedication to detail and excellence
  6. Operator understanding of the subject piping system
  7. Operator understand of corrosion trends at the subject piping system
  8. Surface preparation if required
  9. Field data recording
  10. Volume of data points taken, and their locations
  11. Final data analysis
  12. Capability to draw clear and accurate conclusions

Instrumentation

Having the proper instrumentation, and knowing how to properly use it, is a critically important prerequesite to an accurate ultrasonic evaluation.  Low cost instrument models without a waveform display and / or data logging capability, commonly used, encourage poor quality results.  By providing only a thickness value without the background information showing wave reflection characteristics, the inspector has no confirmation to whether the measurement is accurate or not.  Hand writing the field data, not only introduces an element of potential human error in transcription, but also eliminates any formal record of the thickness value and the instrument settings necessary for later review.

In the photo at left, a lower quality instrument combined with poor operator inspection skills produced a falsely low wall thickness measurement of 0.144 in. at a 30 in. diameter condenser water main header   (This measurement is written on the green painted pipe)  Many additional incorrect low wall thickness measurements to near 0.040 in., and a warning by the UT technician that the pipe could burst at any minute, in turn produced panic within the critical data center facility management group, as certainly understood.

Further inspection by CorrView International, LLC identified a very high and uniform wall thickness still near or above new standard ASTM pipe specifications of 0.375 in., and consistent with all other examples of pipe tested throughout the facility.  In addition to the prior UT inspector producing significantly wrong results at this and all other sections of pipe tested, no evidence to define the reason for such a large error was available through instrumentation that offered no data logging capability and therefore no saved evidence to its accuracy or in this case – inaccuracy.

The lack of an echo-to echo feature to negate the thickness of a painting or coating requires either an unnecessary removal of the paint, an inaccurate global paint thickness deduction for all measurements taken, or more commonly, to ignore the coating thickness completely – thereby producing a falsely high and incorrect wall thickness value.

Experience

We consider that taking wall thickness measurements is far secondary to understanding the forms of corrosion common to the subject piping system.  Dry fire sprinkler systems corrode differently to wet fire pipe, and in different areas.  Condenser water has far greater vulnerability in certain areas of the system than any closed system.  Straight pipe and elbows corrode at different rates, but not due to flow.  Some piping systems have only an interior corrosion concern, while some such as chill water and dual temperature systems have a corrosion threat to both its inside and outside.

Understanding the many piping systems common to any industrial or commercial property allows a skilled investigator to target specifically those areas of greater potential threat, and thereby produce a more useful and informative report.  Random testing, incremental testing every X number of feet, and often testing in the easiest accessible areas of the system, will often exclude those areas of traditionally greatest threat.  Such high priority testing locations are often unknown to those not familiar with specific piping system vulnerabilities – producing a sub-standard and seriously lacking piping assessment as the end result.

Quite often, the report submission itself demonstrates the clear lack of any pride or dedication to excellence, and should reduce any confidence in the results claimed.

Independent Assessment

We offer a very fair and impartial critical review of any pipe testing report submission.  We review its content, presentation, equipment and test methods, thickness data, confidence level, and assess the likely accuracy of the thickness data to the pipe tested.  Obvious inconsistencies, such as a reported 0.500 in. wall thickness for 2 in. schedule 40 pipe, will be flagged as in error.  Conclusions and recommendations are reviewed and critiqued in relation to the test data presented.   A final written report analysis is submitted, along with any appropriate recommendations likely to benefit building operations.

With sufficient backgrond information provided about the piping system, problem conditions, types of failure, etc., we can also offer recommendations toward follow-up steps to take in the form of metallurgical testing, additional UT, remote video inspection – in short, our only interest is to help you better solve the problem at hand, or gain a better understanding thereof.

Such critical review is extremely useful prior to any litigation, and where reliance on a poorly executed investigation, inaccurate data, or unsubstantiated conclusions can either produce an incorrect argument, or allow opposing counsel to easily discount such evidence at trial.