knowledge base
Conventional NDT
MAGNETIC PARTICLE TESTING (MT)
Magnetic Particle Testing (MT) is used to detect surface and subsurface in Ferro-electric/magnetic materials such as iron, nickel, cobalt, and some of their alloys. The process inducts a magnetic field into the part. The piece can be magnetized by direct or indirect magnetization. Direct magnetization occurs when an electric current is passed through the test object and a magnetic field is formed in the material. Indirect magnetization occurs when no electric current is passed through the test object, but a magnetic field is applied from an outside source. The magnetic lines of force travel perpendicular to the direction of the electric current which may be either alternating current (AC) or some form of direct current (DC) (rectified AC).
The presence of a surface or subsurface discontinuity in the material creates magnetic flux leakage. Ferrous iron particles are applied to the part. The particles may be dry or in a wet suspension. If an area of flux leakage is present the particles will be attracted to this area. The particles will build up at the area of leakage and form what is known as an indication. The indication is then evaluated to determine what it is, what may have caused it, and what action should be taken if any.
Applications:
- Ferromagnetic materials
- Surface and slightly subsurface flaws can be detected
- Can be applied to welds, tubing, bars, castings, billets, forgings, extrusions, engine components, shafts and gears
Limitations:
- Detection of flaws limited by field strength and direction
- Needs clean and relatively smooth surface
- Some holding fixtures required for some magnetizing techniques
- Test piece may need demagnetization which can be difficult for some shapes and magnetizations
- Depth of flaw not indicated.
RADIOGRAPHY TESTING (RT)
In Radiography Testing (RT) the test-part is placed between the radiation source and film (or detector). The material density and thickness differences of the test-part will attenuate (i.e. reduce) the penetrating radiation through interaction processes involving scattering and/or absorption. The differences in absorption are then recorded on film(s) or through an electronic means. In industrial radiography there are several imaging methods available, techniques to display the final image, i.e. Film Radiography, Real Time Radiography (RTR), Computed Tomography (CT), Digital Radiography (DR) and Computed Radiography (CR).
FILM BASED RADIOGRAPHY
Industrial radio-graphic methods are not unlike x-rays taken in a hospital. A piece of film is positioned beneath a suspected fracture, radiation directed through it exposes the film. The choice of radiation sources and strength depends on the material composition, size and thickness. The exposed radio-graphic film detects the radiation passing through the material and displays their intensity on the black and white film image.After processing the film it is reviewed to identify and locate any discontinuities or anomalies. The processed film provides a permanent inspection record.
DIGITAL RADIOGRAPHY
Digital Radiography is one of the newest forms of x-ray imaging. Film is replaced by special phosphor screens or micro-electronic flat panel screens. Details can be easily increased and enhanced for expert interpretation. Digital Radiography files are easily shared and archived.
COMPUTERIZED / DIGITAL RADIOGRAPHY
Computerized/Digital Radiography (CR) allows for onsite processing in remote locations. Less radiation is required to produce a higher quality image. Vingrity NDT Services provides our customers with latest in digital technology, a system provided by VMI (Virtual Media Integration). CR is a great method for profile radiography, whether it be for corrosion detection in piping or valves or looking for re-bar or post tension cabling in concrete. It is also getting noticed more and more by standards and codes in the industry for weld quality. CR also provides the customer with a digital image that is stored onto a disk witch provides easier storage and retrieval. So the days of rooms and rooms full of film are coming to an end and everything that you will need can just be a click away on your computer.
Radiography Neutron
Applications
- Metals, non-metals, composites and mixed materials
- Used on pyrotechnics, resins, plastics, organic material, honeycomb structures, radioactive material, high density materials, and materials containing hydrogen
Limitations
- Access for placing test piece between source and detectors
- Size of neutron source housing is very large (reactors) for reasonable source strengths
- Collimating, filtering or otherwise modifying beam is difficult
- Radiation hazards
- Cracks must be oriented parallel to beam for detection
- Sensitivity decreases with increasing thickness
Radiography X-Ray
Applications
- Metals, non-metals, composites and mixed materials
- Used on all shapes and forms; castings, welds, electronic assemblies, aerospace, marine and automotive components
Limitations
- Access to both sides of test piece needed
- Voltage, focal spot size and exposure time critical
- Radiation hazards
- Cracks must be oriented parallel to beam for detection
- Sensitivity decreases with increasing thickness
Radiography Gamma
Applications
- Usually used on dense or thick material
- Used on all shapes and forms; castings, welds, electronic assemblies, aerospace, marine and automotive components
- Used where thickness or access limits X-ray generators
Limitations
- Radiation hazards
- Cracks must be oriented parallel to beam for detection
- Sensitivity decreases with increasing thickness
- Radiation hazards
- Access to both sides of test piece needed
- Not as sensitive as X-rays
ULTRASONIC TESTING (UT)
Ultrasonic Testing (UT) is a portable volumetric examination that uses high frequency sound waves to exam, measure and inspect for thickness, flaws and weakness. Human and material flaws will never be completely eliminated and in-service damage and corrosion require continual “safe use” evaluation.
ULTRASONIC THICKNESS MEASUREMENT
Ultrasonic Thickness Measurement (UTM) is frequently used to assess corrosion, erosion, and mechanical damage of the structural materials on tanks, vessels, piping, castings and structural steel. The testing is accomplished with portable equipment and the results are evaluated to industry standards, codes, or customer specifications. This method can locate and measure the amount of corrosion, erosion or voids within a material. This data is then used to assess the life expectancy of the component or if repairs are required before returned to service.
POCKET UT
Pocket UT is a battery operated, hand held ultrasonic testing system with full C-Scan data display. Portable and easy to use, the Pocket UT™ System along with its available companion scanners and other compatible devices is ideal for on-site inspection applications. The unit is equipped with an internal ultrasonic pulse / receiver, data acquisition software, motion control hardware and software for scanning, signal capture, display, analysis, replay, transfer, and storage. A new cost effective precision testing devise often used in confined or awkward locations. Data can be directly transferred to lap top or desktop computers for further processing or storage. The Pocket UT system is a great method used for scanning and gridding large areas of corrosion and erosion
SHEAR WAVE/ANGLED BEAM
Shear Wave sometimes referred to as Angled Beam Ultrasonic testing is a portable testing method that offers an effective test for weld inspection in pipes, pressure vessels, plates or in areas that other test methods are not feasible or particle. The shear wave method is great for fusion type defects or cracks, whither it is in a weld or on the specimen itself.
Applications
- Metals, non-metals and composites
- Surface and slightly subsurface flaws can be detected
- Can be applied to welds, tubing, joints, castings, billets, forgings, shafts, structural components
- Used to determine thickness and mechanical properties
- Monitoring service wear and deterioration
Limitations
- Usually contacting, either direct or with intervening medium required (e.g. immersion testing)
- Special probes are required for applications
- Collimating, filtering or otherwise modifying beam is difficult
- Sensitivity limited by frequency used and some materials cause significant scattering
- Scattering by test material structure can cause false indications
- Not easily applied to very thin materials
Advantages
- Good penetrating power, allowing for detection of faults deep in the material
- High sensitivity, allowing for detection of very small flaws
- Requires accessibility from just one surface
- Can be more accurate than other nondestructive techniques
- No effect on nearby personnel, operations, equipment or materials
- Instruments are highly portable
Disadvantages
- Requires experienced technicians
- Requires significant technical knowledge
VISUAL TESTING (VT)
Visual Testing is the most common and usually first NDT examination step when the inspector using his eyes to look for defects. The human eye has an amazing ability to differentiate between colors, hues, shapes, sizes contrast and texture. Inspections may require use of magnifying glasses, mirrors for a closer look or viewing material in limited access locations.
Visual inspections are used to detect any visible discontinuities and also to interpret visual data from other NDT processes.
HARDNESS TESTING (HT)
Hardness Testing is the measure of weld and material hardness and the hardness is generally defined as a measure of resistance to indentation. A hardness test gauges this parameter by assessing the depth of an indent or incision made by a precisely shaped Indenters applied to the material with an exact amount of force over a specified period of time. The items that can subject to hardness tests include structural steel, castings, forgings, welds, weld overlays, piping, machined parts and pressure vessels.
Depending on the requirements the following test methods can be used to check the hardness of materials:
Rockwell Test
Hardness Rockwell Testing requires different indenters and loads for different strength or hardness ranges. In addition to gauging hardness, Rockwell numbers can be converted to approximate tensile strength for a number of alloys.
Test material is indented using tungsten carbide tips, except for the Rockwell C scale, which specifies a diamond tip. The tip is forced into the metal under a specified load, usually between 15 and 150 kilograms, and a corresponding value from the Hardness Rockwell scale is determined by the depth of penetration. Test samples can have rounded or flat surfaces and be as small as 5 millimeter square. Hardness Rockwell testing is only conducted on metals and is often used to help ascertain the grade of a metal.
Brinell Test
Hardness Brinell testing utilizes a much larger indenter with higher loads, and subsequently requires thicker samples than standard Rockwell hardness testing. The minimum test material thickness is typically ¼ inches. Brinell test values are derived by measuring the diameter of a circular impression made by a tungsten carbide ball indenter, normally under a load of 500 kilograms or 3,000 kilograms applied for 10 to 15 seconds on iron or steel, and at least 30 seconds for other metals. Penetration depth is measured by a microscope equipped with an optical light source.
Vickers Test
Vingrity uses the Vickers test, also known as a micro-hardness test, to determine the ability of test material to withstand pressure from a standard source. Vickers test calculations are independent of indenter size. As with the Brinell test, values are determined by measuring the depth of an indentation made by an indenter. Tungsten carbide or diamond tips are normally used, along with an optical light source and a microscope.
Knoop Test
The Knoop method is another micro-hardness test procedure, and is used mainly to measure the hardness of smaller, thinner test samples, and when examining case depth. Because the test samples are smaller, they must be very carefully prepared. As with the Vickers method, the Knoop test utilizes an optical measurement system. A rhombohedral-shaped diamond indenter is used for testing in the Knoop scale, and it is more elongated when compared to the pyramid indenter used for a Vickers test. The Knoop method is often used when indentations are close together or close to the edge of a sample. The greater width and shallower depth of a Knoop indentation provides better measurement resolution and makes it more appropriate for testing very thin materials.
POSITIVE MATERIAL IDENTIFICATION (PMI)
Positive Material Identification (PMI) is often required during the construction, installation maintenance and inspection of new and existing industrial equipment including piping systems covered by ASME and API codes. Vingrity NDT Services knowledgeable PMI technicians can quickly identify and verify ferrous and nonferrous alloys with portable XRF equipment. PMI testing equipment sends a low voltage radioactive signal into the tested material. The exposed material returns a group of specific element signals. Each element signal has its own atomic structure which generates a specific energy level. The energy levels are detected and carefully measured to identify the alloys contained in the material. Radiation levels are very low and testing does not damage the material. Results are available immediately after the inspection is completed.
Depending on the requirements, our PMI utilizes either a portable X-Ray fluorescent analyzer or Spark Emission Spectrography to ascertain the different alloys that comprise a particular metal. PMI can be performed on site for almost any size or shape of ferrous and non-ferrous metallic materials, such as welds, castings, forgings, valves, machined parts, pressure vessels, plate material, structural steel or pipe. Both new equipment and equipment already in service are candidates for PMI.
FERRITE TESTING (FT)
Ferrite Testing (FT) is a non-destructive testing method which provides critical data for austenitic stainless steel and duplex materials. The delta ferrite percentage or number allows a technical assessment of material corrosion susceptibility, mechanical properties, service suitability, and service reliability.
To perform properly ferrite testing, both a minimum material thickness and a minimum specimen size are required. Test results are interpreted in accordance with current specifications and/or customer requirements. Reports issued are accompanied when necessary by drawings to identify locations tested.
Applications:
- Austenitic stainless steel/Duplex stainless steels
- Welds (tubing, etc.)
- Normal construction steel with Austenitic chrome alloy steel welded cladding (Ex. Boilers, vessels, etc.)
- Welds, Castings, Forgings, Weld Overlays, Wrought materials
- Weld materials
- Butt/fillet welds
- Category A-D welds
- Stainless weld overlays on non-ferrous interfaces
- In-service and in-construction components
REMOTE ACCESS VIDEO INSPECTION (RAVI)
Remote Access Video Inspections (RAVI) is a safe and popular method of investigating areas and locations that are not accessible by conventional means. RAVI can be employed in situations that pose a potential hazard to workers trying to investigate a situation with conventional techniques.
The use of a small, waterproof and extendable camera means that tight locations can be access for inspection and the results are able to be digitally recorded in either video or still picture format that endure as proof of the inspection findings. This form of inspection has a wide variety of applications and can be used in almost any industry.
One situation where RAVI was employed to great satisfaction of our clients was the investigation of pump & motor installations during the commissioning phase of a chemical plant start-up. RAVI was employed to avoid the otherwise expensive and potentially dangerous situation of accessing the motor & pump entryway to ensure no construction debris remained that could potentially damage or destroy new and expensive pumping systems. Instead of employing a team Piping and Rigging workers to remove large bore pipes to gain access to the tight locations, RAVI was safely employed to investigate and record the results. Because the results were documented in digital format, our client was then able to provide proof to the owners that all passageways were clear and that due diligence had been exercised to ensure damage was avoided to the new machinery.
Typical RAVI applications are:
- Internal Sections of Crane Booms
- Gear Housings
- Normal construction steel with Austenitic chrome alloy steel welded cladding (Ex. Boilers, vessels, etc.)
- Welds, Castings, Forgings, Weld Overlays, Wrought materials
- Weld materials
- Piping Applications
- Insulation Deficiencies
- Cylinder Inspections
- Drains, Traps
- Pumps & Motors
- Automotive Applications
INFRARED/THERMAL IMAGING
Thermal Imaging is the science of detecting energy in the infrared spectrum giving us the ability to detect minute variations in temperature on almost any piece of equipment or structure. Boasting a huge variety of applications Thermal Imaging is the safest form of inspection to help determine the working parameters of any piece of equipment or structure. With applications ranging from ELECTRICAL, MECHANICAL and BUILDING ENVELOPES thermal Imaging can easily be applied to your operation and will provide results that will save you money by allowing you to focus you maintenance efforts where it is needed most – even if you don’t know it.
Typical Thermal Imaging applications:
- Insulation Installations & Deficiencies (Industrial, Commercial, Residential)
- Electrical Inspections and Predictive Maintenance Programs
- Building Envelope Analysis
- Water Damage / Water Intrusion
- Bearings, Conveyor Systems, Rotating Equipment
- Refractory Lining
- Tank / Vessel Inspections
- Asphalt Mixing / Quality Control
HOLIDAY COATING TESTING
Holiday Coating testing detects pinholes and flaws in protective coating that have been applied to conductive materials to protect against corrosion. It is important that flaws are detected early, preferably immediately after the coating is applied. The Holiday Coating test is suitable for most coatings including bonded epoxy, coal tar epoxy, paints, polyester, polyurethane, pipeline tapes, heat shrinks and asphalt. Low voltage tests are conducted on thin coating films. Coatings over .05 mm generally require use of the Higher Voltage Spark Tests. The coatings test is performed by moving a probe across the coated surface until flaws or pin holes are located by voltage “sparks” escaping through the coating and registering on the Holiday Coating testing devise. Discontinuities are marked by Vingrity NDT technicians for repair.
PHASED ARRAY ULTRASONIC TESTING (PAUT)
Increase your productivity with more accurate, safer, environmentally responsible inspection technology while strengthening your reputation as an industry leader. Do you need high volume weld inspections that can be conducted at any time without interference to production? Or perhaps you require weld clearing at short notice and you don’t want to move everyone off the site or out of the shop.
Using advanced Phased Array UT inspection technology as an advanced alternative to radiography. This method can be used to inspect in a busy populated areas with no risk to public safety. This PAUT system is qualified to inspect tubes with diameters ranging from 48mm to 1,524mm and thicknesses from 5mm and greater, in compliance with the ASME Boiler and Pressure Vessel Code Section V.
Advantages:
Semi Automated Phased Array system offers better inspection speed and detection, and makes interpretation of the indications significantly easier.
- Pin Point Accuracy: Always know the exact depth and length of repairs
- Convenient Storage and Retrieval: Instead of hundreds of pieces of film you can store a complete job on one disc
- Free Viewer Download: The TomoViewer™ application, available free online, is all you need to review reports and scans
Other Benefits:
Enhance your reputation for environmental responsibility. Vingrity’s Phased Array system is energy saving, with much less wastage. It virtually eliminates chemicals, fuel and paper and creates a safer working environment for general public.
REMOTE VIDEO INSPECTION (RVI)
Remote Video Inspections (RVI) use fiber optic cameras, borescopes, robotic crawlers and other specialized instruments to conduct remote video inspections (RVI) in numerous industrial applications such as pipe lines, vessels, tanks, turbines, and heat exchangers. Video image data is recorded onto VHS, CD or DVD for viewing and storage.
There are three different borescopes to offer and unlimited scopes that are accessible. The first one that used is Pearpoint’s P374 IS, an intrinsically safe pushrod system certified to EEX ia IIC T6 for Zone 0 Hazardous environments such as vessels or piping within the chemical and petrochemical industries, landfill venting systems, natural gas supply infrastructure, etc. The surface equipment is IP55 rated allowing this system to be used in most types of weather conditions. It is capable reaching 200 feet and has a built in high resolution footage counter. The P374 IS system is compact and fully integrated making it very easy to transport around.
The second system is a Schott Fiber Optics / OPTIM FS-236A is a 6mm x 80” length. This scope is extremely durable and do to the size it can accommodate even the most intricate inspections. It is a hand-held, portable inspection device that combines a high intensity LED light source with a flexible insertion shaft. It is perfect for tighter spots, like small diameter tubing/piping, power generating equipment, castings and vessel inspections.
The third system is the RECON™ Digital Inspection System™ – This digital inspection system is for power and processing industries and provides unrivaled technology, fast set-up time and unprecedented durability that combine for better performance and superior results in inspecting and recording pipe conditions. The RECON system features Everest VIT’s exclusive iVIEW™ platform that allows images to be manipulated, stored or copied for remote or in-the-field assessment of quality or damage control. This system features interchangeable camera heads, LED lighting and is capable of reaching 30 feet in length; therefore, it is great for a large variety of applications such as boiler tubes, down combers, steam lines, electrical conduits, process lines, heat exchangers and even infrastructures.
Vingrity is CWB Certified
Vingrity is also a CWB (Canadian Welding Bureau) Certified Inspection Organization as per CSA standard for the below product categories to conduct VT. MT and UT.