AVN Professional Quality FZE and AVN Non-destructive Testing Services offers top-of-the-line services pertaining to  non destructive testing in Dubai, UAE.

Non destructive Testing (NDT) is used to assess integrity of industrial materials such as rolled, forged, casted and welding. NDT is a wide group of analysis techniques used in science and technology industry to evaluate the properties of a material, component or system without causing damage. The terms nondestructive examination (NDE), nondestructiveinspection (NDI), and nondestructive evaluation (NDE) are also commonly used to describe this technology. Because NDT does not permanently alter the article being inspected, it is a highly valuable technique that can save both money and time in product evaluation, troubleshooting, and research.

Benefit From High-Quality Non-Destructive Testing In UAE

The six most frequently used NDT methods are eddy-current, magnetic-particle, liquid penetrant, radiographic, ultrasonic, and visual testing. At AVN Professional Quality FZE and AVN Non-destructive Testing Services, we provide NDT services as listed below:

• Visual Inspection / Testing (VT)
• Liquid Penetrant Testing (PT)
• Magnetic Particle Testing (MT)
• Ultrasonic Testing (UT)
• Ultrasonic Thickness Measurement (UTM)
• Vacuum Box Testing (VBT)
• Positive Material Identification (PMI)
• Coating Thickness Measurement (CTM)
• On-site Portable Hardness Test (HT)

Visual inspection, with or without optical aids, is the original method of NDT. Many defects are surface-breaking and can be detected by careful direct visual inspection.

Visual examination is the most basic non-destructive testing method, which precedes and is used in conjunction with any other NDT method. Visual inspection is a method that ranges from simply looking at a part to see if surface imperfections or defects are present and visible, to using Optical aids include low-power magnifiers, microscopes, telescopes and also specialized devices such as borescopes, endoscopes and other fibre-optic devices for the inspection of restricted access areas.

Liquid penetrant testing is a traditional non-destructive method for inspection of surface breaking flaws such as cracks and porosity in test objects with non-porous surfaces.　 The tested surface is cleaned and coated with a penetrant solution either a visible or fluorescent dye that is drawn into the discontinuity by capillary action. The excess solution is removed from the surface, but the penetrant remains in the surface breaking flaws. A white developer is then applied to draw the penetrant out of the defects and shows a contrast image. After the evaluation of the indications the surface is cleaned.

Liquid penetrant testing can be used on relatively dirty surfaces, but the sensitivity is decreased, but a fluorescent penetrant can also be used that gives increased sensitivity.　 The length of an indication can be accurately determined, but the depth cannot be determined with this method.

Magnetic particle testing is a widely established non-destructive method for the detection of surface breaking flaws as well as sub-surface flaws with depths of 2-3mm. The method is accomplished by inducing a magnetic field in ferromagnetic materials. The surface is coated with a white contrast paint and over this paint iron particles suspended in liquid are applied. Surface and near surface flaws produce magnetic poles and iron particles are attracted and concentrated, producing a visible indication of the defects on the surface of the material. The length of an indication can be accurately determined, but the depth cannot be determined with this method.

Ultrasonic methods of NDT use beams of mechanical waves (vibrations) of short wavelength and high-frequency, transmitted from a small probe and detected by the same or other probes. Such mechanical waves can travel large distances in fine-grain metal, in the form of a divergent wave with progressive attenuation.

The technique detects internal, hidden discontinuities that may be deep below the surface. Transducers and coupling wedges are available to generate waves of several types, including longitudinal, shear and surface waves. Applications range from thickness measurements of thin steel plate to internal testing of large turbine rotors.

Ultrasonic testing techniques are widely accepted for quality control and materials testing in many industries, including electric power generation, production of steel, aluminium and titanium, in the fabrication of air frames, jet engine manufacture and ship building.

Because in ultrasonic pulse-echo testing the time of travel of the pulse to a reflector is measured and displayed, it is a very simple adaptation to use this measurement as a thickness gauge. Low-cost small hand-held instruments are available, and the usual read-out is a digital display rather than an oscilloscope screen. Such thickness gauges require either calibration or a knowledge of the ultrasonic velocity in the material under test.

One of the most basic ultrasonic methods applied is using a zero-degree dual transducer probe to send an ultrasonic beam into a component and receiving the ultrasound energy bounced back from the far wall of the component. Thus, a pulse-echo technique, where the time travelled from the excitation pulse to the first echo signal is used to determine the material thickness. These tests are normally done with probe frequencies ranging from 5 to 10 MHz and can measure thicknesses from 0.7mm to 200mm, and in temperature ranges of -5 ºC to 500 ºC.

Vacuum box testing is a non-destructive examination used when trying to locate weld seam leaks. A vacuum box and a compressor create a high- or low-pressure vacuum while a detergent solution is applied to the test area. The detergent bubbles, making leaks visible within the created pressure envelope.

Positive material identification (PMI) is used to analyses and identify material grade and alloy composition for quality and safety control.
A rapid, non-destructive method, positive material identification is performed on a wide range of components and assets and provides a semi-quantitative chemical analysis. It is used for both material verification and identification.

The method is utilized for quality control and safety compliance and is an integral part of both production and asset integrity management across many industries including oil and gas, power, chemical, pharmaceutical, nuclear, aerospace and fabrication.

Various methods of NDT are used for the measurement of coating thickness – paint thickness, plating thickness, anodising etc. These methods may be X-ray, electron backscatter, magnetic, etc.

Portable Hardness Testing (HT) is a non-destructive testing method utilized to obtain the hardness value of a material. AVNNDT uses the latest Portable Hardness Testing Technology to provide clients the information they require about the materials they are utilizing.