Consulting Services
Expert Witnes, Forensic Investigation, Fitness For Service, Acquisition, General Advice |
For most of the ultrasonic investigations we become involved, only unsupported speculation originally exists to the severity, extent, and cause of the corrosion problem. Six different involved individuals involved with a corrosion problem often means that there are 6 different and often mistaken opinions based upon no hard facts whatsoever. Unfortunately, substantial cost and valuable time is wasted pursuing the wrong direction before the facts of the corrosion problem are finally established.
CorrView International, LLC approaches every corrosion question as a forensic investigation - pursuing hard evidence, documenting and then proving pipe condition through the use of well established ultrasound technology. We also provide additional services directly related to ultrasonic testing and the field of corrosion control and mitigation; with a large resource of other successful professionals to call upon when required.
Expert Witness
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We believe in bringing overwhelming evidence and proof of a corrosion problem to the table in any litigation. To establish and firmly document a corrosion problem and degree of damage to a piping system so thoroughly and irrefutably that no possible defense exists. The same primary intent and attitude exists for disproving a corrosion problem as well. Given the poor quality and inaccuracy of most ultrasonic reports, some bordering on inept, this is not at all difficult. While other forensic methods of proof to a corrosion problem are often also appropriate, such as metallurgical testing and internal robotic video inspection, it is a thorough ultrasonic evaluation which is almost always the first critical step necessary in order to steer additional investigation to the most appropriate and informative piping areas. |
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Forensic Investigation
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We approach each ultrasonic piping evaluation as an investigation rather than a procedure. That is, to adapt and modify the focus of the investigation as it progresses, rather than strictly test pipe every 20 ft., 100 ft., 500 ft., etc. To thoroughly identify and proove (or disprove) the conditions taking place, multiple disciplines may be required. (Please see our article on this subject in the British journal World Pipelines) In many investigations metallurgical testing will be necessary to determine the underlying cause of the corrosion problem or failure, with ultrasonic testing able to direct the most appropriate example of pipe to remove rather than cut it out randomly with the hope of blindly selecting the most appropriate location. Elsewhere, microbiological testing, and even DNA analysis may be required to confirm a microbiologically influenced corrosion (MIC) condition. For further confirmation to the prediction of high rust deposits, clogged pipe, or to inspect areas of pipe behind walls and inaccessible, remote video inspection (RVI) provides the best inspection tool. |
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Pre and Post Construction Material Verification
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An FM or UL label and official stamp on pipe is assumed to define it suitable for installation and at ASTM factory specifications. But in fact, steel pipe can be + / - 12.5% of those specifications and still be approved for service. Today, most steel pipe and some copper is produced substantially undersized due to what we believe are closer manufacturing tolerances enabling manufacturers to produce a lighter but still approved product within the limits of the ASTM code. Extensive testing of new steel pipe has consistently found undersized material statistically beyond the possibility of being a random event. The combination of lower than expected pipe wall, more corrosion susceptable steel, less effective chemical inhibitors, and higher corrosion levels, frequently adds up to severe corrosion problems at new systems that were unheard of decades ago. By installing a fixed testing template at various locations throughout a new piping installation, and prior to the introduction of water, a baseline of pipe wall thickness can be established and compared to true ASTM specifications. Such proactive planning allows precise follow-up ultrasonic testing during the early stages of system commissioning, chemical cleaning, pressure testing, and flushing - where the highest wall loss typically occurs. Future thickness testing then has a known baseline to more accurately define corrosion rate activity, and potentially suggest the need for corrective actions years before a corrosion problem might otherwise reveal itself. |
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Peer Review |
A substantial volume of ultrasonic testing by supposedly qualified individuals is performed poorly in terms of accuracy and procedure. It is not uncommon to see reported wall thickness measurements which are totally beyond the realm of possibility. For example, a report of 12 in. schedule 40 pipe having both a 0.0350 in. and 0.745 in. wall thickness within the same limited section - impossible. An even greater volume of the resulting written reports from such work are incompetently preparared, inaccurate in terms of measurements taken, and therefore entirely worthless. A typical ultrasonic report is often an Excell spreadsheet of a few wall thickness values and nothing else. Either way, questionable information is provided upon which critically important and often costly decisions will be made. Where questions have been raised to the wall thickness results and conclusions based thereof, a second critical and independent review and assessment of the raw data is always recommended. Such review will immediately highlight inaccurate or unlikely thickness measurements. It will also define whether seemingly accurate wall thickness measurements have been properly interpreted in terms of estimating corrosion rate activity and remaining service life. |
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Pre-Renovation Assessment - Fitness For Service
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Considering the older age of most building properties under renovation, defining the condition of its piping system at the earliest stages of planning and design is a highly worthwhile precaution against future conflict. Different piping systems corrode and offer varying service life to others. In addition to age, maintenance and chemical protection varies greatly to prevent any reliable speculation to its condition and future fitness for service. For some properties aged 100 years, testing has identified little to no wall loss from schedule 80 specifications and another 200 years of service at least. For others, testing at 10 year old systems have shown high corrosion activity and the pipe at the end of its useful service life. Too often, however, investigation is only initiated after prior leaks, repairs, or some piping problem has been exposed during renovation. As we have documented too many times, it is far too late identifying that 20 sets of perimeter risers are failing and in need of replacement on all 30 floors with the renovation project half way completed. A thorough and accurate ultrasonic examination of relevant piping systems is always the best first step to any renovation project at older as well as newer building properties. |
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Insurance |
Ideally, the best insurance provides ideas and recommendations to minimize exposure to a corrosion problem and prevent pipe failures from ever occurring. Yet for some, insurance is the fallback after the most basic and appropriate maintenance precautions have been ignored. Although many large insurance underwriters conduct regular property inspections, they generally fail to recognize those hidden threats common to specific piping systems. Looking at a pipe from the outside, except where multiple pipe clamps are in view, tells nothing of its internal condition and remaining service life. |
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Property Acquisition |
With potentially hundreds of millions of dollars of investment involved, defining the condition of the piping infrastructure prior to purchase is an extremely wise decision. Older properties, which may be approaching retirement for many piping systems, are not the only concern - with even 5 year old properties today showing advanced failures unheard of decades ago. A thorough fitness for service investigation ensures against surprise failures and expendatures which often remain hidden during more general engineering due diligence surveys. |
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Material Condition Assessment
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Preparation to any welding to a live piping system or tank, such as for a wet tap or future servce, often requires validation to the remaining wall thickness of the piping or metal surface. This is of special concern where internal corrosion is known to exist and for older properties where no record of materials used is available or current condition known. Ultrasonic testing is ideal for this function and will provide immediate information about existing wall thickness along the proposed welding zone. |
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Advice & Consultation
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We offer free advice and consultation over the phone when available. Although it is often difficult to pinpoint the cause or define the extent of a corrosion problem by description alone, useful insight and recommendations can often be provided. Submitting high resolution photographs of any removed piping sections, repairs, corrosion product, prior test reports, or other relevant examples of the piping system will often provide excellent information useful in our speculation to the cause. For minimal cost, we can also ultrasonically test and evaluaten pipe sections which have been cut out and shipped to our office. While not the same as a full ultrasonic investigation relating to 60 or more piping examples, any hard data will always provide useful insight. |
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Product And Services Referral
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With over 30 years of experience in the field of corrosion control, testing, and monitoring, we have worked with many highly qualified experts and sources of valuable information in associated fields such as water filtration, corrosion control, pipe lining, pipe rehabilitation, high pressure water jet cleaning, metallurgical testing, etc. We have also met our share of near idiots who have caused more harm than good, and have a file folder filled with grossly inaccurate ultrasonic testing reports; incompetent on even a 5th grade level. Sad to say. CorrView International does not represent others nor sub-contract their work. At request, we will instead suggest contacting those companies which have provided effective and proven solutions in their field should their services seem appropriate. |
Full understanding of a corrosion concern is often best started by a review of any existing information - such as prior ultrasonic testing reports, metallurgical or lab analysis, and ideally, photographs of the piping concern, rust deposits, pipe interior, etc.
Please feel free to send any such relevant information via our Upload Page.
© Copyright CorrView International, LLC
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Installed in an isolated loop, corrosion coupons never suffer the same environmental effects as the pipe itself, and rarely provide accurate test results. Hardened deposits, electrical activity, under deposit corrosion, micro biological buildup, flow effects, and other common environmental factors typically do not exist for corrosion coupons. A flow requirement, by definition, prevents their installation in precisely those locations traditionally showing the highest corrosion threat. In addition, installing corrosion coupon racks at multiple points throughout a circulating system is not practical and is almost never performed - thereby forcing the unlikely assumption that the test results shown for one specific location are representative over the entire piping system.
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Periodically cutting out samples of pipe for metallurgical analysis is extremely expensive, usually requires a system shutdown, is rarely carried out for large diameter piping, and for any critical or 24/7 operation - is virtually impossible to perform. Combined maintenance and metallurgical costs can easily exceed $4,000 per sample. Metallurgical analysis does offer valuable information unavailable through any other means, and is especially useful in order to identify the cause of a corrosion condition, but is generally limited in use due to its cost and inconvenience. Metallurgical analysis usually plays an inportant role in defining a corrosion problem, rather than discovering one.
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Spool pieces, which are nothing more than removable sections of actual pipe within the system, provide valuable information regarding the actual net effect of corrosion activity against the pipe surface. Unfortunately they are only applicable for smaller diameter piping separate from the main lines. Properly installed, spool pieces offer a true inside look at deposits, surface pitting, inhibitor and cleanout effectiveness, as well as provide samples for micro biological cultures. Like corrosion coupon racks, however, they are rarely installed throughout a piping system and enjoy limited use.
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Ultrasonic wall thickness testing provides the greatest volume of reliable data, and will typically produce a thorough corrosion evaluation as long as a sufficient number of test points are taken. Ultrasound is often used as a prerequisite to other testing methods due to its low cost and wide coverage, or as a confirmation that wall thickness conditions known to exist in one area do or do not exist elsewhere within the piping system. It is most often used as a tool to identify the pnbsp; nbsp; nbsp; 4080nbsp; MIDDLE /nbsp; bsp;nbsp;nbsp;sp;extent of an a =nbsp;p;nbsp; nbsp;nbsp;p;nbsp;nbsp;nbsp;nbsp;lready recognized leak or rusting problem, and long term corrosion monitoring using ultrasound requires establishing specialized testing procedures. Read more about ultrasonic pipe testing.
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A wide variety of electronic techniques eixst to produce an estimate of corrosion rate generally based upon the principal of Linear Polarization Resistance, or LPR. LPR provides the benefit of an immediate corrosion measurement that can be routed to monitoring electronices, or data logged for download, and offers an extremely useful corrosion measurement tool. LPR is generally expensive to install and maintain. Regular celaning and calibration is often required, and even then, results may not approximate true corrosion activity - expecially if underdeposit corrosion or MIC is active.
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The insertion of a remotely controlled camera into the pipe offers a valuable thought very limited inspection option. Its use requires the system to be out of service and drained, and is greatly limited by access into the piping system. Pipe size, physical configuration, internal conditions, and length of travel offer further restrictions in its use. Remote Video Inspection (RVI) cannot provide any wall thickness data, but can quickly locate those internal indications that wall loss has occurred - such as tubercular deposits, deep pitting, or suspected MIC growths. Combined with ultrasound or metallurgical testing, RVI can quickly and cost effectively document whether similar problem conditions exist in other areas of a piping system.
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X-ray offers limited application for a piping evaluation primarily due to its high cost and safety concerns. While x-ray can provide the wall thickness values necessary for a true pipe condition analysis, it is most often used for the inspection of weld integrity or for identifying cracks, voids, or a major localized deterioration in a pipe material. Cost, health, and environmental issues severely restrict its use in all but the most critical of applications.
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Similar technology also exists for an excellent but rarely used tool in measuring a wide variety of piping related problems. Its use of safe, low powered gamma radiation rapidly identifies areas of higher wall loss - quickly locating those areas in need of further investigation. By detecting variations in metal density, this hand held device can also detect pipe blockages, identify wet insulation, show liquid level, or confirm pipe schedules, etc. |

P.O. Box 8513
Landing, NJ 07850
www.corrview.com
Ph: 973-770-7764
Fax: 973-770-6576