Nondestructive Examination

nondestructive inspection on oil pipe


Nondestructive Examination (NDE) enables the inspection of structural components and systems without permanently altering the equipment.

Because it allows inspection without interfering with a product’s final use, NDE provides a balance between quality control & cost-effectiveness.

NDE is a highly valuable technique that is used to detect instabilities, validate the integrity of materials, discover performance outside of tolerances, recognize failed components, or expose inadequate control systems.


Ultrasonic Testing (UT) techniques are used to measure material thickness in a wide variety of industries, both for manufacturing quality control and for in-service monitoring.

A major advantage of NDE is the ability to precisely measure wall thickness in places where access is limited to only one side of a test piece, as in a pipe, vessel, or tank, or where simple mechanical measurement is impossible or impractical for other reasons, such as part size or access limitations.

Ultrasonic thickness gauges can be used on virtually any engineering material, including most metals, plastics, glass, ceramics, rubber, fiberglass, and composites.


Used for finding surface/near surface defects in ferromagnetic material, Magnetic Particle testing (MT) is a versatile inspection method used for field and shop applications.

Magnetic particle testing works by magnetizing a ferromagnetic specimen using a magnet or special magnetizing equipment. If the specimen has a discontinuity, the magnetic field flowing through the specimen is interrupted and leakage field occurs. Finely milled iron particles coated with a dye pigment are applied to the specimen. These are attracted to leakage fields and cluster to form an indication directly over the discontinuity. The indication is visually detected under proper lighting conditions.

Magnetic particle inspection can use either wet or dry magnetic media. The dry method is more portable, while the wet method is generally more sensitive since the liquid carrier gives the magnetic particles additional mobility. Indications that are formed after applying the magnetic field must be interpreted by a skilled inspector. This requires the individual to distinguish between relevant and irrelevant indications.

The following are the advantages of magnetic particle inspection:

  • Can detect both surface and near subsurface indications.
  • Can inspect parts with irregular shapes easily.
  • Pre-cleaning is not as critical as for some other inspection methods.
  • Fast method of inspection and indications are visible directly on the specimen surface.
  • Considered low cost compared to many other NDE techniques.
  • Very portable inspection especially when used with battery powered equipment. 
man using scanning equipment on pipe


Liquid Penetrant Testing (PT) is a widely applied and low-cost inspection method used to locate surface-breaking defects in all non-porous materials (metals, plastics, or ceramics).

PT is used to detect casting, forging, and welding surface defects such as cracks, surface porosity, leaks in new products, and fatigue cracks on in-service components. 


Visual Inspection (VT) is a common method of nondestructive examination using some or all of raw human senses such as vision, hearing, touch and smell and/or any non-specialized inspection equipment to inspect parts and equipment.

Inspections requiring UT, MT, and PT are not typically regarded as Visual Inspection as these inspection methodologies require specialized equipment. All EEI Visual Inspectors are experienced, specially trained, and certified by API, AWS, and/or ACCP.


Positive Material Identification (PMI) is the analysis of a metallic alloy to establish composition by reading the quantities by percentage of its constituent elements.

This is done using an X-Ray Fluorescence (XRF) analyzer. This machine is highly portable and can record numerous readings in different locations over a relatively short timescale.


  • Leak Testing
  • Tank Settlement Survey
  • Tank Roof Seal Inspection
  • Helium Leak Testing of Roof Pontoons
  • Vacuum Box Testing
  • Holiday Testing
  • Borescope Inspection
  • Portable Hardness Testing