From the Field

Corrosion Fatigue and Thermal Fatigue Cracking Detected in Boiler Tubes With Hawkeye

The Problem:

A power plant in New Jersey experienced a failure in a slag screen tube in one of their boilers.  Following the rupture, the “S” shaped tube was removed and analyzed.  The results of the metallurgical analysis identified corrosion fatigue cracking and thermal fatigue cracking as the reasons for the rupture.  The corrosion fatigue cracking, which originated on the internal surface of the tube, was a result of corrosive elements introduced into the system by a leak in the … Read the rest

Corrosion Detected In Pipelines using LFET

The Problem:
A former refinery site in Illinois is currently in the process of reclaiming the polluted land on which it sits. A major component to the reclamation of this brownfield site is the pumping of groundwater underneath the former refinery. The water is then treated to remove the contaminants. This also lowers the water table underneath the refinery, forcing surrounding groundwater to flow into the low spot. With this system in place, the contamination will not spread throughout the … Read the rest

Inspection of a Vessel Containing Corrosive Material

Problem:

A major chemical company in Virginia needed an on-stream inspection of a vessel to determine its reliability. The product in the vessel is highly corrosive to the material of the vessel, so it is lined with a Teflon coating. Due to a faulty pump leaking product onto the vessel numerous times, the surface was heavily pitted on the outside surface. It was determined an API 510 inspection would give the needed information as far as the extent of the … Read the rest

Furnace Tubing in Reducing Gas Furnace

Problem:

A mining company in Venezuela was experiencing localized wall loss on the inner diameter (ID) of their furnace tubing in the Reducing Gas Furnace.  Attempts to use A-Scan Ultrasonics proved inconclusive as insufficient back wall signatures were observed.  The company had been replacing furnace tubing at scheduled periods to avoid in-service failures while continuing the search for a method of identifying sections of tube that exhibited ID corrosion/thinning.  The tubing material was rare and expensive (ASTM-A297 Modified Nb).  TesTex, … Read the rest

Line Cat Used in Alaska Pipeline Inspection

Problem:

A large petroleum producer in Alaska was forced to shut down a 34” diameter crude transit pipeline in August 2006, due to a leak in the line. The leak, found at the six o’clock position, was caused by MIC attack. The company wanted to test the line using a pig, but with the uncertainty regarding the integrity of the line, and the environmental issues involved, they had to be sure that the line could hold the pressure necessary for … Read the rest

Scanning 2200 Oil & Gas Above Ground Storage Tanks

Problem:

A major Oil and Gas Company, with oil and gas well sites located in the Texas Panhandle and Western Oklahoma, was experiencing problems with their above ground storage tanks due to heavy production and sour crude. Most of the tanks were found to have internal corrosion within the lower 8” of the tank shell. In addition, this company did not have an accurate inventory of the equipment at the well sites. The company wanted the lower 16” of each … Read the rest

TesTex LFET Inspection vs B&W EMAT Inspection

Problem:

A power plant located in Texas was experiencing numerous problems in their #3 Boiler. The furnace of the #3 Boiler is comprised of approximately 24,000 linear feet of 2.5” OD, 0.203″ and 0.300”; nominal wall thickness smooth bore carbon steel water wall tubing. The unit was experiencing tube failures due to I.D. pitting, corrosion cells, and hydrogen damage. Many destructive samples verified both the location and severity of several defects initially found with the Low Frequency Electromagnetic Technique (LFET) developed … Read the rest

Ultrasonic Thickness Inspection of Above Ground Tank

Problem:

A large Chemical plant in Kentucky that produces synthetic compounds was suspecting wall loss in a vertical process tank. Areas of pitting and uneven surfaces were visually observed at a distance during scheduled outages, but due to accessibility, no quantitative data could be obtained. The engineers at this facility needed to know if this tank was reliable enough to be used productively and safely in the upcoming months. A forced outage would bring down the entire process line until … Read the rest

Boiler Generating Bank Inspection – Pitting Detected – using RFET

Problem:

A large chemical plant in Eastern Tennessee was experiencing a number of tube leaks in one of their boiler generating banks. The cause for the failures consisted of two specific flaw mechanisms revealed through destructive tube samples, which are listed below:

  1. ID pitting as small as 3/16” diameter occurring between the mud drum tubesheet and mud drum bend, which was mainly found on the cold side.
  2. ID longitudinal grooves as small as 1/8” in width located between the steam

    3. … Read the rest

Horizontal Reheater Tube Leak Detected with Low Profile Scanner

Problem:

A large utility plant in Western Pennsylvania, with three identical boilers, experienced a tube leak in one of Unit #3’s horizontal reheater pendants. The cause for the failure was oxidation pitting due to out of service corrosion. Destructive samples showed ID pitting as small as 3/16” diameter occurring on the bottom half of the tubes.

Inspection from the ID was not possible due to accessibility. In addition, the 90 and 180 degree bends would prevent a probe from negotiating … Read the rest

Hawkeye-2000 vs Magnetic Particle & Dye Penetrant Methods

Problem:

A major Pulp and Paper Mill in the Southern Michigan area needed a Deaerator Tank inspected during their summer outage per insurance company requirements. Because of manpower and budget constraints, the mill sought to avoid the grit blast surface preparation that was necessary for Magnetic Particle and Dye Penetrant Inspections.

The customer’s goal was to have the seam and attachment welds in the tank inspected in one shift with minimal cleaning. Plant personnel wanted the inspection crew to stay … Read the rest

Ultra High-Speed Eddy Current Condenser Tube Inspection

Problem:

A large utility in the Southeast United States was experiencing a high rate of tube leaks in one of their main condenser units. The unit was repeatedly forced offline due to these leaks and other related boiler problems. Locations of the leaks were sporadic and could not be isolated to any given area. The unit was due for re-tubing, however, this was not to be performed for another 1-2 years. The customer needed to inspect all the tubes in … Read the rest

Papermill in Virginia Uses Eagle 2000 RFET System

Problem:

A prominent, high volume paper mill in Virginia was experiencing generating bank tube failures believed to be due to soot blower erosion. This boiler was the plants main steam generator and was critical for the plant to run at capacity. External tube inspections such as spot U.T. were not viable options due to the limited space in between the tubes and the lack of coverage area. Accordingly, the client needed an I.D. tube inspection method. The plant needed a … Read the rest

Carbon Steel Heat Exchanger Inspection Using RFET

Problem:

A major chemical plant in Western Pennsylvania asked TesTex to perform a partial inspection (50 percent) of the 324 tubes in one of their heat exchangers on a scheduled plant shut-down. TesTex and the plant contact agreed on an “every other tube” test pattern. The exchanger consisted of 1.0″ O.D. 0.065″ wall carbon steel seamed tubes (SA-214). The tubes were 8 feet long with contact to 14 baffle plates. TesTex used the Eagle 2000 Digital Inspection System and the … Read the rest

Boiler Feedwater System Pinholes Found with Eddy Current

Problem:

A large utility in the Northeast United States was experiencing water in-leakage in their boiler feedwater system due to pinholes in their Stainless Steel condenser tubes. It was determined that these pinholes were located underneath deposits in the tubes, thus making the leak undetectable by off line hydro or dye testing until the deposit was removed by cleaning.

These small pinholes developed due to deposits laying on the inside of the tube over a period of time. The in-leakage … Read the rest

TesTex Falcon 2000 Mark II Tank Floor Inspection System

Problem:

A large well known oil refinery in the United Kingdom gave TesTex the opportunity to show our ability to inspect the floor of an Above Ground Storage Tank in comparison to the spot check U.T. in use by the refinery. The TesTex Falcon 2000 Mark II Digital Tank Floor Inspection System operates on the principles of the TesTex proprietary Low Frequency Electromagnetic Technique (LFET). Some of the advantages of the Falcon 2000 Mark II System include minimal cleaning, the ability … Read the rest

Hawkeye Crack Detection

Problem:

A prominent, high volume manufacturing company in Montana was experiencing generating bank tube failures due to cracking in one area of their Riley Stoker Hog Fuel boiler. This unit had been operating under increased steam production, causing low steam drum water levels therefore affecting the upper portion of the tubes.

After submitting a failed tube sample to a metallurgical lab, it was determined that the cracks were most likely due to thermal fatigue initiating on the exterior/OD of the … Read the rest

Search TesTex-NDT.com

Pages

Translation

Signup for Our Feed

Click the icon to subscribe to the feed.