In industrial piping environments, there are many situations where defects in materials and/or the welds of the materials must be detected to ensure quality control. The defects may be internal flaws such as cracks, voids, etc. produced during the manufacturing of the material, flaws in the area of a weld due to inadequate welding preparation and/or practice, or surface irregularities due to, in most cases, corrosion.
A preferred method for detecting these flaws is called non-destructive testing, or inspection. In non-destructive testing, flaws are detected by various methods such as ultrasonic, x-ray, magnetic particle and electro-magnetic. Historically the majority of pipe or tube inspection has been done by x-ray. More recently ultrasonic methods are being used.
The key problem with x-ray inspection is the hazards associated with handling radioactive materials and equipment. The entire work area must be flagged and vacated during inspection which often causes job delays. Conventional Ultrasonic equipment does not require the work area to be vacated but is often too bulky to be used in applications with tight space requirements. Many chemical plants, refineries, and nuclear plants often have piping and tubing spaced closely together. Emerging ultrasonic phased array technology has now made it possible to use ultrasonic inspection in these tight applications. Conventional scanning hardware on the market is too large and bulky to be used in many of the piping and tube application where space is limited. This leaves the operator no choice but to translate the probe along the material's surface by hand.