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

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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.

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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.


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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.

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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.

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Dead Zones

The Leading Cause Of Pipe Failure At Condenser Water Systems

Despite various corrective measure, advanced failures at condenser water systems are on the rise. Many problems are engineered into the system from the start due to the failure to recognize the impact rust deposits and particulates have on producing higher secondary corrosion levels. In addition, most corrective measure, if they are attempted, fail to provide a solution. Here is why.

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Undersized Steel Pipe

A Simple Dial Caliper Measurement Of New Steel Pipe May Reveal Surprising Results

In addition to the many corrosion influences negatively impacting piping systems, many new building properties are constructed using carbon steel pipe which is below factory specification. To the surprise of many, an FM or UL approval, like its ASTM stamp, does not define that the pipe actually meets ASTM thickness standards.

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Inevitable Corrosion

The Decline In The Quality Of Today’s Piping Products Means Greater Corrosion Problems

A large number of negative influences have comined to produce a higher frequency of corrosion problems – often in spite of all precautionary measures taken. Of those, lower quality pipe, undersized pipe, more complex piping layouts, and generally less effective chemical treatment options have produced a “Perfect Storm” contributing to more piping failures.

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Corrosion Threats

When Pipe Corrosion At A Fire Protection System Can Cost Lives

The time to learn of a fire pipe corrosion problem is not during an actual fire emergency. Internal rust deposits can, and have, totally blocked water flow through the sprinkler heads – resulting in the loss of human life. More common at dry systems, internal deposits are a serious threat to all fire protection systems.

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Fire System Failures

Major Misconceptions Within The Fire Protection Industry

Ignoring the obvious does have serious consequences when it comes to fire protection systems. From the use of thin wall schedule 10 & 7 pipe, to lower quality pipe products, to frequent flow testing which brings in new fresh water, clear and well documented reasons exist to explain the higher corrosion activity found at today’s fire protection systems.

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Fire System Corrosion

The Threat Of A High Corrosion Condition To A Fire Sprinkler Line

Often viewed only in terms of water damage in the case of a corrosion induced pipe failure, far more serious concerns exist, although rarely considered. Unlike HVAC piping systems, corrosion activity at fire related piping can impede and in some cases totally block water flow – a potentially life threatening condition during any fire emergency

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Ultrasonic Testing

The Benefits of Ultrasonic Testing in Determining Corrosion Rate and Service Life

Ultrasonic testing provides the most comprehensive, accurate, and cost-effective tool to assess the condition and remaining service life of any piping system. Planned and performed properly, ultrasound offers the first step toward identifying a potential corrosion problem, or for certifying a piping system as fit for service.

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Corrosion Influences

Why Not All Pipe Failures Are The Fault Of Your Chemical Water Treatment Provider

Various design elements to any piping system can have dramatic impact upon its corrosion activity. Pipe origin, schedule used, physical layout, and many other unknown factors can produce a pipe failure. And yet they are completely beyond the realm of protection offered by chemical water treatment.

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Corrosion By Design

Pipe Corrosion Problems No Water Treatment Program Can Protect Against

Various changes have occurred to mechanical piping designs over the past few decades, with virtually all HVAC, plumbing, and fire protection systems having been affected in some way. Many changes relate to the materials themselves. Major changes in piping design, however, have introduced new corrosion problems no chemical treatment program can stop.

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Corrosion Coupons

The Benefits and Limitations of Corrosion Coupons

Relied upon for decades as an indicator of corrosion activity within piping systems, corrosion coupons are highly unreliable in most examples, and totally worthless in others. Many of the most damaging corrosion failures have occurred while at the same time corrosion coupons produced excellent results. Here is why.

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Unexpected Failures

If Corrosion Activity Is Only 0.4 MPY, What Is Wrong With The Above Picture?

Corrosion coupons reported a 0.4 MPY corrosion rate for 6 years where the actual rate exceeded 25 MPY. Believed implicitly in contrast to multiple leaks and failures, the slow but total destruction of the entire condenser water piping system was the net result. A case history illustrating the threat from relying exclusively upon this highly flawed testing method.

Dry Fire Sprinkler

Fire Protection Contractor – Antifreeze: The Fine Line Between Hero and Defendant

Antifreeze used in dry fire sprinkler systems may solve one problem, but has also proven deadly. Rated a Class 1 flammable liquid, antifreeze can accelerate a fire, create a fireball, and even cause an explosion. Although now restricted to lower concentrations, antifreeze still adds heat value to any fire and introduces new and unknown liability to any such system.

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Corrosion Trends

American Welding Society – Understanding Pipe Corrosion Problems

A piping system that satisfies service life demands, requires the recognition of piping design vulnerabilities, effective corrosion monitoring, and the adoption of corrective measurements. With corrosion related failures on the rise, and with generally lower quality pipe being installed, advanced planning and an awareness of potential threats becomes more important.

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Testing Procedures

World Pipelines – Investigation vs. Procedure

Substantially different findings are likely where ultrasonic pipe testing is approached as a forensic investigation based upon known system problems and vulnerabilities, rather than simply a linear based measurement procedure. A critical importance is understanding the inherent corrosion related problems to various piping systems. An adapting investigation will also produce a more definitive answer to any piping problem.

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Fire Pipe Corrosion

Fire Protection Contractor – When Pipe Corrosion In a Fire Protection System Can Cost Lives

The time to first learn of a pipe corrosion problem is not during a true fire emergency when lives are in jeopardy. Thinner pipe, more corrosive steel, lower quality galvanizing, foreign pipe, dry systems, MIC – all such negative factors are driving toward higher internal corrosion deposits to render your fire protection system worthless.

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Ultrasonic Testing

Fluid Handling Systems – Finding The Remaining Service Life

Ultrasonic testing is, by far, the most informative diagnostic method available for determining pipe status, as well as extremely cost effective. An effective piping analysis is much more than a spreadsheet of a few wall thickness measurements – requiring careful statistical analysis and practical interpretation of the data.

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Pipe Corrosion

World Pipelines – Multiple Metering And Monitoring Needs

With no single form of corrosion monitoring capable of proving full coverage to the many different forms of pipe corrosion possible, multiple testing methods are always advised. These should include ultrasonic testing, spool pieces, LPR, regular internal inspection, and a close observance to the often obvious but missed signs of a problem.

A 30+ Year Knowledge Base

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Corrosion

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Failure

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Repair

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Replacement

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Unfortunately, the above is a very common progression of events for many of our clients. Often, greater attention to chemical corrosion control and corrosion monitoring could have saved the system and avoided the problem. In others, a decades prior design flaw or poor choice of pipe supplier may be traced back as the primary fault.

During the 20 years that we have been involved in the field of ultrasonic pipe testing / corrosion monitoring, we have authored various Technical Bulletins for the benefit of our clients. These Technical Bulletins address frequent problem issues to any building owner or operator, and offer both insight as well as reasonable and proven solutions.

We offer below the various categories available, and continue to add new bulletins as time permits.

Current Categories

Interior Rust Deposits, Common Threats, Corrosion Types, Winter Lay-Up, MIC, Corrosion Monitoring and Testing, CUI, Corrosion Coupon Failures, Rust Removal, Reducing Corrosion Threats, Roof Level Corrosion, Drained Pipe, Corrosion Trends, Fire Sprinkler Corrosion, Corrosion At “Free Cooling” Systems


The Impact Of Flow Rate To Higher Corrosion, Inadequate Water Filtration, Piping Layout Design, “Green” Piping Designs


Corrosion Threats, Design Misconceptions, Interior Rust Deposit Threat, Dry Fire System Corrosion, Schedule 10 Pipe, Premature Failures, Clogged Fire Systems, Chemical Control Options, Remediation Choices


Condition Assessment, Due Diligence, Preparation Prior To Renovation, System Evaluation, Expert Witness


Heat Exchangers, Benefits of UT Testing, High Pressure Water Jet Cleaning, Filtration Errors, Chemical Treatment, Condenser Tube Coating, Mold Concerns, Chromate Removal, Growing Threat of Corrosion, Heat Exchanger Tub Coating, Nondestructive Testing


Schedule 40 Limitations, Piping Trends, Hidden Corrosion Threats, Dielectric Insulators, Clamped Grooved Piping, Piping Schedules, Pipe Testing Specification, Roof Pipe Draining, Low Corrosion Guidelines, Dual Temperature Piping Failure


Cold Water Threats, External Corrosion Issues, Fire Reserve Tanks, Interior Pitting, Protective Coatings, Rehabilitation


Improving Heat Transfer Efficiency, Improving Filtering Efficiency, Filter Placement, Poor Performance Causes, Filter Selection Considerations


Chemical Treatment Challenges, Limitations to Water Treatment, Corrosion Coupon Reliance