- Specialized Ultrasonic Testing
- Electromagnetic Testing for Tubular
- Floormap MFL
- Guieded Wave Testing GUL G4
- Remote Access Ultrasonic Crawler
- Acustic Emission AE
- AUTOMATED UT CORROSION MAPPING
- ULTRASONIC PHASED ARRAY WELD INSPECTION
- TIME OF FLIGHT DIFRACTTION (TOFD)
- INTERNAL ROTARY INSPECTION SYSTEM (IRIS)
ULTRASONIC CORROSION MAPPING
Corrosion mapping by ultrasonics is a technique which maps material thickness using ultrasonic techniques. Variations in material thickness due to corrosion can be identified and graphically portrayed as an image. The technique is widely used in the oil and gas industries for the in-service detection and characterization of corrosion in pipes and vessels. The data is stored on a computer and may be color coded to show differences in thickness readings.
To perform corrosion mapping an automatic or semi-automatic scanner is used to scan an inspection surface, using various ultrasonic techniques including pulse echo, eddy current and phased array. Corrosion mapping is widely used in the oil, gas and nuclear industries for the inspection of pipework, pressure vessels, storage tanks and reactors. In the Aerospace sector, corrosion mapping is often referred to as ‘C-Scan’ for the inspection of ferrous and no ferrous materials. Results for corrosion mapping provide a high degree of repeatability and the advantage of position and size data for every flaw which can be compared for repeat scans of the same area to track flaw growth or corrosion rates both generally and for individual pits.

BENEFITS
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- faster data collection
- High sensibility and high degree of repeatability
- All boiler and fired heater tubes, furnaces.
- Position and size data for every flaw can be compared for repeat scans of the same area to track flaw growth or corrosion rates both generally and for individual pits
- Automatically generated visual reports
- Easy to interpret result
- Can be used in material by 3mm to 8 plg of wall thickness
- Automated inspection is ideal for areas that are inaccessible or difficult to access with other methods such as radiography, requiring minimal access considerations
- Rapid and accurate analysis – same day and next day reporting available, depending upon complexity and finding
LIMITATION
- Areas on test material must be accessible to scanner(s) with no immediate obstructions to scan areas.
- The scan surface must be in a clean condition; thin wall paints and other coatings are acceptable if no disbonding, flaking or other anomalies are present.
- Coarse grained materials can present problems for ultrasonic techniques.
- Non-ferrous materials need to have alternative methods of securing the scanner to the material surface
- Geometry of the part and accessibility, are deciding factors on the extent of capable UT
ULTRASONIC PHASED ARRAY WELD INSPECTION

APPLICATION
Phased array ultrasonics (PA) is an advanced method of ultrasonic testing that has applications in industrial nondestructive testing. Common applications are to find flaws in manufactured materials such as welds.
Phased array is widely used for nondestructive testing (NDT) in several industrial sectors, such as construction, pipelines, and power generation. This method is an advanced NDT method that is used to detect discontinuities i.e. cracks or flaws and thereby determine component quality. Due to the possibility to control parameters such as beam angle and focal distance, this method is very efficient regarding the defect detection and speed of testing. Apart from detecting flaws in components, phased array can also be used for wall thickness measurements in conjunction with corrosion testing. Phased array can be used also for the following industrial purposes:
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- Inspection of welds
- Thickness measurements
- Corrosion inspection
- Flaw detection
- Rolling stock inspection (wheels and axles)
BENEFITS
- Accurate and detailed images of weld abnormality.
- Higher probability of detection compared with conventional methods.
- Simplify the inspection of components with complex geometries.
- Full digital data storage for auditing and/or future reviews.
- Significantly increased productivity (for volume inspections).
- Fully code compliant with ASME and EN standards.
LIMITATION
- Surface must be accessible to transmit ultrasound.
- Skill and training is more extensive than with some other methods.
- It normally requires a coupling medium to promote the transfer of sound energy into the test specimen.
- Materials that are rough, irregular in shape, very small, exceptionally thin or not homogeneous are difficult to inspect.
- Satinless steel and other coarse grained materials are difficult to inspect due to low sound transmission and high signal noise.
- Linear defects oriented parallel to the sound beam may go undetected.
- Reference standards are required for both equipment calibration and the characterization of flaws
TIME OF FLIGHT DIFFRACTION (TOFD)

APPLICATION
Time-of-flight diffraction (TOFD) method of ultrasonic testing is a sensitive and accurate method for the nondestructive testing of welds for defects. TOFD originated from tip diffraction techniques that Measuring the amplitude of reflected signal is a relatively unreliable method of sizing defects because the amplitude strongly depends on the orientation of the crack. Instead of amplitude, TOFD uses the time of flight of an ultrasonic pulse to determine the position and size of a reflector.
In a TOFD system, a pair of ultrasonic probes are placed on opposite sides of a weld. One of the probes, the transmitter, emits an ultrasonic pulse that is picked up by the probe on the other side, the receiver, in undamaged pipes, the signals picked up by the receiver probe are from two waves: one that travels along the surface and one that reflects off the far wall. When a crack is present, there is a diffraction of the ultrasonic wave from the tip(s) of the crack. Using the measured time of flight of the pulse, the depth of a crack tips can be calculated automatically by simple trigonometry.
The common application of TOFD is together with Phased Array in the weld and material inspection.
BENEFITS
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- Based on diffraction, so relatively indifferent to weld bevel angles and flaw orientation
- Uses time of arrival of signals received from crack tips for accurate defect positioning and sizing
- Precise sizing capability makes it an ideal flaw monitoring method
- Quick to set up and perform an inspection, as a single beam offers a large area of coverage
- Rapid scanning with imaging and full data recording
- Can also be used for corrosion inspections
- Required equipment is more economical than phased array, due to conventional nature (single pulser and reciever) and use of conventional probes
- Highly sensitive to all weld flaw types

LIMITATION
- Surface must be accessible to transmit ultrasound.
- Skill and training is more extensive than with some other methods.
- It normally requires a coupling medium to promote the transfer of sound energy into the test specimen.
- Materials that are rough, irregular in shape, very small, exceptionally thin or not homogeneous are difficult to inspect.
- The dead zone created by the lateral wave signal just below the inspection surface (or OD surface in case of the pipe),The dead zone is approximately 5 mm and there is no flaw detection in this zone.
INTERNAL ROTARY INSPECTION SYSTEM (IRIS)

APPLICATION
Internal rotary inspection system (IRIS) is an ultrasonic method for the nondestructive testing of pipes and tubes. The IRIS probe is inserted into a tube that is flooded with water, and the probe is pulled out slowly as the data is displayed and recorded. The ultrasonic beam allows detection of metal loss from the inside and outside of the tube wall.
With the IRIS (internal rotary inspection system), we can inspect tube by Heat Exchangers, Boilers, Air Coolers and Feedwater Heaters, This technique uses a water driven rotating mirror to direct an ultrasonic beam, which is re directed 90 degrees to the internal tube wall, The water column generated by the probe assembly acts as a water couplant and transmits sound waves from the ultrasonic transducer to the tube wall. The ultrasonic transducer is mounted axially in the tube and the beam is directed toward the mirror, which is placed at a 45-degree angle to the transducer. The mirror is supported on a water driven turbine that spins on an axis parallel with the probe axis. Using special ultrasonic electronics a B-scan pattern of the (cross-sectional pro le) tube wall is presented.

BENEFITS
- Inspection of Ferromagnetic and nonferromagnetic tubing.
- Provides accurate wall thickness readings.
- Can distinguish between I.D. and O.D. defect orientation.
- Allows detection and sizing of wall loss such as corrosion, pitting, erosion and bafle wear.
- Can inspect .500” up to 3” diameter (larger size with special probe design).
- Can be used as a backup technique with RFT, NFT and/or MFL inspection.
- Inspect approximately 150 to 200 tubes in an 8 hour day based in 180Ft of Long.

LIMITATION
- Cleanliness of the tubes is a major factor and requiresthorough tube cleaning removal of all scale, deposits,chemical residue and/or oil residue prior to inspection
- Slow Inspection Speeds of 15 tubes / hour.
- Cannot detect cracks (Special probe design is needed).
- Cannot inspect Low Fin Tubing.
- TLimited to isolated pit detection and pit size (=> 1/8”diameter).
- Outside of scale, a rough ID surface can reduce theeffectiveness of the examination as well
REMOTE FIELD ELECTROMAGNETIC TESTING (RFET)

APPLICATION
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- Remote field testing (RFT) is an electromagnetic method of nondestructive testing whose main application is finding defects in steel pipes and tubes. RFT may also referred to as RFET (remote field electromagnetic technique). An RFT probe is moved down the inside of a pipe and is able to detect inside and outside defects with approximately equal sensitivity (although it can not discriminate between the two)
- The basic RFT probe consists of an exciter coil (also known as a transmit or send coil) which sends a signal to the detector (or receive coil). The exciter coil is pumped with an AC current and emits a magnetic field. The field travels outwards from the exciter coil, through the pipe wall, and along the pipe. The detector is placed inside the pipe two to three pipe diameters away from the exciter and detects the magnetic field that has travelled back in from the outside of the pipe wall (for a total of two through-wall transits). In areas of metal loss, the field arrives at the detector with a faster travel time (greater phase) and greater signal strength (amplitude) due to the reduced path through the steel. Hence the dominant mechanism of RFT is through-transmission.
BENEFITS
- Suitable for ferromagnetic materials
- No need for direct contact with the pipe wall
- Less sensitive to probe wobble than conventional eddy current testing
- Only one surface needs to be accesible.
- Equal sensitivity at the inner and outer surface
- Highly sensitive to variations in wall thickness
- Because the field travels on the outside of the pipe, RFT shows reduced accuracy and sensitivity at conductive and magnetic objects on or near the outside of the pipe, such as attachments or tube support plates
- Can be inspect tube up to 75mm of diameter and 5 mm of thickness
- Can be inspect up to 500 tube by 10 hour work day
LIMITATION
- Not a quantitative technique for identifying remaining wall thickness
- Some limitation to distinguishing ID from OD defects.
- Evaluation of small flaws such as pits can be difficult (10% or less)
- Requires high inspection skills for data analysis and evaluation.
- Aplication is only in ferromagnetic materials.
- Tubes must be cleaned.
- Inaccuracy in test results could occur if a discontinuity encountered differs in geometry from calibration discontinuities.
- Is necesary a calibration block with the same geometric that the tube to inspect.
EDDY CURRENT TESTING (ETC)

APPLICATION
The two major applications of eddy current testing are surface inspection and tubing inspections. Surface inspection is used extensively in the aerospace industry, but also in the petrochemical industry. The technique is very sensitive and can detect tight cracks, corrosion and wall loss.
Tubing inspection is generally limited to non-ferromagnetic tubing and is known as conventional eddy current testing. Conventional ECT is used for inspecting steam generator tubing in nuclear plants and heat exchangers tubing in power, oil and petrochemical industries. The technique is very sensitive to detect and size pits. Wall loss or corrosion can be detected but sizing is not accurate.
A technique that is often used involves feeding a differential bobbin probe into the individual tube of the heat exchanger. With the differential probe, no dsignal will be seen on the eddy current instrument as long as no metal thinning is present. When metal thinning is present, a loop will be seen on the impedance plane as one coil of the differential probe passes over the flawed area and a second loop will be produced when the second coil passes over the damage. When the corrosion is on the outside surface of the tube, the depth of corrosion is indicated by a shift in the phase lag. The size of the indication provides an indication of the total extent of the corrosion damage
BENEFITS
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- Suitable for NO-ferromagnetic materials.
- No need for direct contact with the pipe wall
- Equal sensitivity at the inner and outer surface.
- DHighly sensitive to variations in wall thickness.
- Can be inspect tube up to 75mm of diameter and 5 mm of thickness.
- Can be inspect up to 700 tube by 10 hour work day.
- portable test equipment is very small and light, some of the latest equipment being as small as a video cassette box and weighing less than 2kg.

LIMITATION
- Not a quantitative technique for identifying remaining wall thickness.
- Eddy current inspection is Only suitable for conductive materials.
- Surface must be accessible to the eddy current probe.
- Skill and training required to carry the Eddy current testing and interpretation of results is more extensive than other techniques.
- Surface finish and roughness may interfere in properly analyzing the Eddy current testing results.
- Reference standards needed for setup for every eddy current inspection.
- Depth of penetration is limited in Eddy Current inspections.
- Flaws such as circuferential crack that lie parallel to the probe coil winding and probe scan direction are undetectable
MAGNETIC FLUX LEAKAGE FOR TUBULAR (MFL)

APPLICATION
MFL is a technique used for the inspection of tubes made of ferrous materials. This technique will normally be applied as a fast screening technique if small diameter pitting is expected. Because of limitations to its sizing abilities the technique is not often used as a stand –alone technique.
MFL can also be used on air n cooler tubes. MFL is sensitive to sharp type defects like pits and grooving. In- and external pits can be detected. Depending on probe con guration MFL can distinguish between in-and external defects and can detect gradual wall-loss. For ID/OD discrimination the probe needs to be equipped with a second coil and to detect gradual defects a Hall-effect sensor in the probe is needed.
BENEFITS
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- Evaluates tube of fin fan cooler of Ferrous Material.
- Quick and Cost Effective and Requires no Couplant thus is a “Dry Application”.
- Reliable and repeatable results.
- Can be inspect tube up to 75mm of diameter and 5 mm of thickness.
- Can be inspect up to 500 tube by 10 hour work day.

LIMITATION
- Not a quantitative technique for identifying remaining wall thickness.
- Requires ultrasonic follow up where indications of wall loss are found.
- Poor surface conditions (scale, debris, roughness, and certain coatings) may limit the integrity of the inspection.
NEAR FIELD TESTING (NFT)

APPLICATION
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- Near field testing is used for the inspection of fin fan carbon steel tubing in heat exchangers tubes it was first developed as an alternative to magnetic flux leakage (MFL). Specifically designed to detect internal corrosion, erosion, or pitting on the inside of carbon steel tubing. Because the eddy current penetration is limited to the inner surface of the tube, NFT probes are not affected by the fin geometry on the outside of the tubes.
- NFT is a technology that uses two coils — a transmitter and a receiver. Typically the receiver coil is close to the transmitter coil, taking advantage of the transmitter’s near-field zone — that is, the zone where the magnetic field from the transmitter coil induces strong eddy currents, axially and radially, in the tube wall. NFT is also much more sensitive to defects close to structures such as support plates and tubesheets.
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The inspection weld in new fabrication or repair according to the reference codes:
- ASME B31.1 and B31.3 for new piping
- ASME Section VIII for Pressure Vessels
- API 650 for tank
- API 1104 for pipelines
- AWS D1.1 for structure
BENEFITS
- Most ideal for fin-fan type heat exchanger tubes – Aluminum finned Carbon Steel tubes
- NFT is excellent for detecting tube internal discontinuities.
- NFT is ideal for detecting internal corrosion, erosion, pitting and axial cracking
- NFT can detect discontinuities near support plates and tubesheets with high sensitivity
- Very fast as compared to other electromagnetic test methods
- NFT is not affected by the external support structures or tubesheets
- Can be inspect tube up to 75mm of diameter and 5 mm of thickness
- Can be inspect up to 500 tube by 10 hour work day

LIMITATION
- Not a quantitative technique for identifying remaining wall thickness
- Skill and training required to carry the NFT and interpretation of results is more extensive than other techniques
- Reference standards needed for setup for every NFT inspection
- Depth of penetration is limited in NFT inspection
- Only inspect inner surface of the tube
MAGNETIC FLUX LEAKAGE IN TANK BOTTOM (MFL)

APPLICATION
Magnetic flux leakage is a magnetic method of nondestructive testing that is used to detect corrosion and pitting in steel structures, most commonly pipelines and storage tanks. The basic principle is that a powerful magnet is used to magnetize the steel. At areas where there is corrosion or missing metal, the magnetic field "leaks" from the steel. In an MFL (or Magnetic Flux Leakage) tool, a magnetic detector is placed between the poles of the magnet to detect the leakage field. Analysts interpret the chart recording of the leakage field to identify damaged areas and to estimate the depth of metal loss, MFL can be used in the range of 6 to 12 mm all ferromagnetic tank bottoms . Furthermore, limited coated surfaces can easily be tested.
The Floormap system produces a detailed geometrical view of the inspected area. This view immediately provides the operator with an understanding of the tank bottom – basically the operator can determine the nature and geometry of the indication meaning the following questions can be answered; is the indication due to a weldment or corrosion? Is the indication wide or deep?.
The Floormap introduces a new high contrast plate view based on the intensity of the MFL signal response. The MFLi defect map uses multiple colour palettes to highlight areas of corrosion, reduce the effect of spurious indications and can be used to classify defect type.
This powerful detection and classification tool can reveal the presence of small diameter pitting, SRB attack, erosion patterns and other features that require further verification.

BENEFITS
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- Evaluates Tank Bottom Condition on Bottom Plates of Ferrous Material.
- Quick and Cost Effective and Requires no Couplant thus is a “Dry Application”
- Steerable Fast Motor Driven Scanner to minimize the time examination.
- Features “discontinuity floor map” Functionality.
- Ruggedized Touch Screen Technology for Ease of Use Within the Storage Tank Environment.
- Available with the Full Sized MFL Scanner and/or with the Smaller Motorized MFL Mini-Scanner and MFL Manual Scanner.
- Reliable and repeatable results.
LIMITATION
- Not a quantitative technique for identifying remaining wall thickness.
- Requires ultrasonic follow up where indications of wall loss are found.
- Poor surface conditions (scale, debris, roughness, and certain coatings) may limit the integrity of the inspection.
- Internal tank components close to the floor limit the access to particular areas.

LONG RANGE GUIDED WAVE ULTRASONIC TESTING (GWUT)

APPLICATION
Guided Wave testing (GWT) is one of latest methods in the field of non-destructive evaluation. The method employs mechanical stress waves that propagate along an elongated structure while guided by its boundaries. This allows the waves to travel a long distance with little loss in energy, guided wave technology is now commonly used as a complementary screening tool to improve corrosion detection in various pipeline, the technology may be applied to thin- and thick-walled pipe, with diameters ranging from 4” to 60”, rapidly and economically. Use reliable engineering data to assess exactly where your pipeline needs follow-up nondestructive or visual inspection.
With guided wave, low-frequency waves are sent along pipe; these waves propagate over long distances, covering 100% of the pipe wall thickness from a single inspection position. Guided wave testing is used to identify areas of concern, which are then locally scanned with conventional UT or phased array to size the indication, ensuring that the rest of the line is free of corrosion.

BENEFITS
- Rapid screening for in-service degradation (Long range inspection) - potential to achieve hundreds of meters of inspection range.
- Detection of internal or external metal loss
- Reduction in costs of gaining access - insulated line with minimal insulation removal, corrosion under supports without need for lifting, inspection at elevated locations with minimal need for scaffolding, and inspection of road crossings and buried pipes.
- Data is fully recorded.
- Fully automated data collection protocols.
- Good sensibility in the inspeccion (minimal threshold is wall loss of 3% cross-section area ).
- Inspect approximately 150 to 200 tubes in an 8 hour day based in 180Ft of Long.
LIMITATION
- Interpretation of data is highly operator dependent.
- Difficult to find small pitting defects (area of loss below 3% of the cross-section area).
- Not very effective at inspecting areas close to accessories.
- To high temperature >75 Gr. C is necessary other accesories.
- TLimited to isolated pit detection and pit size (=> 1/8”diameter).
- Needs good procedure.
- To buried pipe other procedure is neccesary.

CRAWLER REMOTE ACCESS ULTRASONIC INSPECTION

APPLICATION
Dry-coupled remote access ultrasonic crawler system brings major efficiency and data improvements to the inspection of structures such as storage tanks, vessels and offshore installations. Scorpion CRAWLER is equipped with the best ultrasonic electronics and software the industry has to offer. With its advanced filtering, the system can inspect materials ranging from 5 to 100 mm (0.2 to 4 in) faster and more accurately. The software allows for unique UT gate processing, such as floating and tracking gates, ensuring correct wall thickness measurements under most circumstances.
The battery-power crawler is designed to go where no man can go. Crawler handling is minimized with simple controls and long umbilical, when combined with a speed of up to 180 mm/sec (7 in/sec), allow the completions of inspections faster and more efficiently.

BENEFITS
- faster data collection.
- efficient scanning patterns.
- higher probability of detection.
- ability to collect valuable measurements in critical locations
- Is not necesary scaffolding to make thickness measurement in oil wall tank.
LIMITATION
- Areas on test material must be accessible to scanner(s) with no immediate obstructions to scan areas.
- The scan surface must be in a clean condition; thin wall paints and other coatings are acceptable if no disbonding, flaking or other anomalies are present.
- Coarse grained materials can present problems for ultrasonic techniques.
- Non-ferrous materials need to have alternative methods of securing the scanner to the material surface.

ACUSTIC EMISSION AE

APPLICATION
The application of acoustic emission to non-destructive testing of materials typically takes place between 100 kHz and 1 MHz. Unlike conventional ultrasonic testing, AE tools are designed for monitoring acoustic emissions produced by the material during failure or stress, and not on the material's effect on externally generated waves. Part failure can be documented during unattended monitoring. The monitoring of the level of AE activity during multiple load cycles forms the basis for many AE safety inspection methods, that allow the parts undergoing inspection to remain in service.
AE-testing is a method for screening active corrosion and active leakage in storage containments. The test method exploits acoustic emissions of corrosion process or leaking medium. It is a non-intrusive method without the need of opening and cleaning the storage containment prior to inspection. The result of an AE-test poses a recommendation for a maximum operation period until a subsequent inspection is necessary.
BENEFITS
- Is non-intrusive.
- Can be performed on in-service equipment.
- On-line monitoring of components and systems.
- Leak detection and location.
- Real-time evaluation.
LIMITATION
- Acoustic emission can be subject to extraneous noise.
- AE assessments are qualitative.
- hey do not characterize flaws or corrosion damage in terms of flaw, orientation, size and/or depth.
- The structure under test will attenuate the acoustic stress wave.
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