Vibrant NDT Services Pvt Ltd

Phased array ultrasonics (PA) is an advanced method of ultrasonic testing that has applications in medical imaging and industrial nondestructive testing. Common applications are to non-invasively examine the heart or to find flaws in manufactured materials such as welds. Single-element (non-phased array) probes, known technically as monolithic probes, emit a beam in a fixed direction. To test or interrogate a large volume of material, a conventional probe must be physically scanned (moved or turned) to sweep the beam through the area of interest. In contrast, the beam from a phased array probe can be focused and swept electronically without moving the probe. The beam is controllable because a phased array probe is made up of multiple small elements, each of which can be pulsed individually at a computer-calculated timing. The term phased refers to the timing, and the term array refers to the multiple elements. Phased array ultrasonic testing is based on principles of wave physics, which also have applications in fields such as optics and electro-magnetic antennae.

Although time-of-flight diffraction (TOFD) can be used for a variety of applications, its primary use is rapid weld testing of circumferential and axial weld seams, also known as perpendicular TOFD scanning. Since the introduction of TOFD in the 1970s, the use of this reputed reliable nondestructive testing technique has steadily increased. Manual execution is possible with TOFD, however, it is most commonly performed in combination with a recording device, that is, an encoder or industrial scanner. To achieve code compliance in North America, TOFD is often coupled with pulse-echo or phased array techniques to cover the root and cap regions of the weld.

Popular TOFD Weld Inspection Techniques

TOFD can be used independently or in conjunction with other ultrasonic techniques. Some of the most common techniques are:

• Single group TOFD
• Multiple TOFD
• TOFD with pulse-echo/creeping waves
• TOFD with phased array

Magnetic flux leakage (MFL) 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 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.

Ultrasonic Plate Inspection

Rolled Steel plates used in Automobile Industries and Aluminum & Titanium plates intended for aerospace applications are inspected in accordance with stringent industry standards. The large size of the plates and their wide thickness range demand high inspection productivity. Defect evaluation and comprehensive inspection reports are common requirements.

Vibrant NDT has developed a highly efficient field-proven, high throughput plate inspection solution designed to provide a complete solution for material testing and handling. Vibrant Team uses either a phased array or conventional transducers for defect detection and includes advanced features for plate scanning, data acquisition, defect evaluation, and reporting based on the application.

NDT is a basic need for Industries like Power Plants and refineries to ensure safety and reliability. Components like Heat Exchangers and condensers need to be checked periodically from inside these plants since a leak of any kind can lead to productivity loss and more importantly serious environmental hazards.

Heat exchangers and steam Generator tubes in power plants, especially Nuclear power plants, need to be inspected for leaks periodically to prevent hazards. Hence, identifying and replacing damaged and weak parts is a very important task and ensures a safe process and reliability.