Traditional NDT solutions
With technicians based around the UK, we offer a comprehensive range of industry proven Traditional NDT techniques to BS / EN / ASNT code and standards.
Services at our Rotherham facility include:
LIQUID PENETRANT INSPECTION
Benefits of LPI:
- Used on a wide range of materials
- Large areas or large volumes can be inspected rapidly
- Parts with complex geometries can be inspected easily
- Visual of the anomaly on material
- Aerosol spray cans can make equipment very portable
MAGNETIC PARTICLE Inspection
Used for finding surface/near surface defects in ferromagnetic material, Magnetic Particle Inspection (MPI) is a versatile Traditional NDT inspection method used for field and shop applications. Magnetic particle testing works by magnetising a ferromagnetic specimen using a magnet or special magnetising equipment. If the specimen has 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. The basic procedure that is followed to perform magnetic particle testing consist of the following:
- Pre-cleaning of component
- Introduction of Magnetic field
- Application of magnetic media
- Interpretation of magnetic particle indications
It is essential for the particles to have an unimpeded path for migration to both strong and weak leakage fields. Therefore, the component in question should be clean and dry before beginning the inspection process. The presence of oil, grease or scale may compromise the inspection.
Benefits of MPI:
- Detect surface and near subsurface indications
- Can inspect parts with irregular shapes easily
- Pre-cleaning is not as critical
- Indications are visible directly on the specimen surface
- Low cost compared to many other NDT techniques
- Very portable inspection
Industrial radiography is used for a variety of applications but is commonly performed using two different sources of radiation, X-Ray and Gamma ray sources. The choice of radiation sources and their strength depends on a variety of factors including size of the component and the material thickness. Within the broad group of X-Ray and Gamma ray sources are a variety of camera choices with varying radiation strengths.
MISTRAS Services X-Ray capabilities run the gamut from 4 MEV units utilised to radiograph extremely large and thick castings and forgings, to portable X-Ray cameras used for field weld applications and thin wall material inspection. Gamma sources vary from very low level fluoroscopic units to perform real time corrosion under insulation surveys, to Iridium (Ir192) and Selenium (Se 75) sources used for a variety of weld inspections, to Cobalt (Co 60) inspections for thick component testing.
There are many advantages to radiography including: inspection of a wide variety of material types with varying density, ability to inspect assembled components, minimum surface preparation required, sensitivity to changes in thickness corrosion, voids, cracks and material density changes, the ability to detect both surface and subsurface defects and the ability to provide a permanent record of the inspection. The disadvantages of radiography are: safety precautions are required for the safe use of radiation, access to both sides of the specimen are required, orientation of the sample is critical, and determining flaw depth is impossible without additional angled exposures.
Benefits of UT:
- Detects surface and subsurface defects
- Depth of penetration vs. other test methods is superior
- Only single sided access is required with a pulse-echo technique
- High accuracy regarding estimating discontinuity size and shape
- Minimal specimen preparation is required
- Instantaneous results produced by using electronic equipment
- Detailed images can be produced with automated systems