Underwater NDT Inspections
Underwater repairs, maintenance and inspection for the international merchant fleet.
Underwater NDT Inspection
FN Diving performs the following underwater NDT Inspection methods when needed with Diver Technicians holding CSWIP 3.1 up to 3.4.
- Visual
- MPI/Magnetic Particle Inspections
- Eddy Current Inspections
- Ultrasonic Inspections/Thickness measurements
FN Diving Underwater NDT instruments are calibration checked prior to each use to ensures accurate measuring information
NDT MPI Crack Testing
Magnetic particle inspection (MPI) crack testing involves determining the extent of a crack in ferrous metals which may not be visible to the eye. When the extremities of the crack are located often stop drilling technique is required or other supplementary preventative measures.
MPI crack testing can be carried out in the wet or dry using FN Diving magnetic particle inspection (MPI) UV crack testing system in combination with trained personnel.
Some cracks can extend above the water line requiring the MPI to be deployed above and below the water line and this is achievable using our MPI systems.
The identified linear indication is documented using underwater photography and real time video.
NDT Metal Thickness Measuring
Underwater Metal thickness measuring is commonly performed to determine the current state of the structure when compared to its original design whether for class or intermediate Survey of submerged objects.
FN Diving uses calibrated aproved thickness gauges for accurately measuring the metal thickness underwater in digital readout and is supported with the aid of underwater photography and video
Eddy Current
As eddy current is best used for detecting surface-breaking cracks. Its most practical applications relate to the in-service inspection of welded structures, that are subject to a cyclical loading that can lead to fatigue crack propagation in critical welded areas.
Eddy current is good for detecting surface-breaking defects. Eddy current can detect these defects through fairly thick coatings (up to 2 mm), underwater several scans of an individual weld must be performed to ensure a defect is not missed. Eddy current is an operator-dependent technique.