Materials and equipment develop defects such as fatigue cracks or corrosion cracks, on being used regularly. Undetected defects may at a later stage require expensive repair or may result in equipment failure. Common weld defects include Lack of fusion, Porosity, Cracking and Undercut. Such defects affect the stress distribution along the weld and may lead to failure.
Non-Destructive Testing (NDT) is the practice that makes sure that the materials, equipment and components affirm to the required specifications. When NDT inspection is carried out, safeguards are taken to ensure that the equipment or component does not alter its usefulness and serviceability. JABCO Inspection Services has expertise in performing Non-Destructive Testing to determine the integrity and reliability of the equipment and components in use.
We make use of the following NDT methods.
The condition of a weld or component is evaluated by using this inexpensive inspection method. Testing under this technique requires the inspector to have knowledge about the correct appearance of the weld, good vision and good lighting.
When a reliable conclusion is not possible to be drawn by visual examination, we use the following Non-Destructive Tests (NDT) methods to further assess the integrity and reliability of the equipment.
Magnetic Particle Testing (MPI)
By this method cracks or discontinuities on or near the surface of ferromagnetic and electrically conductive materials is detected. The test involves producing a magnetic flux in the material by creating a magnetic field externally or allowing electric current to pass through the material. Ferrous particles are sprinkled on the test surface when the magnetic flux is alive and these particles get attracted and accumulated to the edges of the cracks or discontinuities if they are present in the material. It is an effective method for detecting surface or sub-surface defects in steel plate, castings, forgings, high weld areas etc.
Penetrant Testing (PT)
Also known as Dye or Liquid Penetrant Test, it is a widely used method to locate surface-breaking defects in non-porous materials. In this method, the test object is coated with a visible dye solution. If any imperfections exist on the surface they get revealed after a while. The method is used for locating defects in castings and forgings as well for fatigue cracks in-service castings.
Ultrasonic Testing (UT)
High-frequency ultrasonic waves are used in this method to detect surface breaking and internal imperfections on ferrous and non-ferrous materials. It is a highly useful method and accurate method to evaluate internal product integrity, as ultrasound penetrates deeply into the materials and reveals correctly the defects, cracks, delamination, lack of bonding and other discontinuities.