What is Alternating Current Field Measurement (ACFM)?
ACFM originated out of a need to inspect offshore structures without removing protective coatings. Today, ACFM works for both offshore and onshore applications. Alternating Current Field Measurement works by introducing a uniform current into any electrically conductive material. Upon the introduction of the current, the magnetic field is detected and tested near the surface of the area being tested. This allows a measurement of any disturbances in the field which indicate a damage mechanism (cracks).
Advantages of ACFM
Periodically our customers require special application inspection of weldments in large structural joints and those located in the interior of pressure vessels. The ACFM technology allows for a thorough investigation of those weldments and areas of the base metal adjacent to those welds. The system is excellent in identifying surface breaking anomalies that are hidden under painted surfaces.
The inspection procedure is ideal for inspecting and screening large amounts of weld footage in a short time frame. Once areas of concern are identified, conventional magnetic particle inspection is deployed to define those suspected surface anomalies.
Additionally, the system components are lightweight and are easily managed in tight work environments such as plant pressure vessels in turnaround applications. The system is also transportation friendly for offshore destinations that rely on air transportation.
Alternating Current Field Measurement (ACFM) Services
- Vessel head and longitudinal seam welds, both interior and exterior
- Highly stressed joints on offshore drilling and production units
- Large areas of weld seams on aboveground storage tanks that have been subjected to deformation from external sources
- The ACFM system is easily managed by rope access personnel for elevated work in refinery and chemical plant applications
- The ACFM technology is extremely useful in upper joint inspections of the underside frame work of offshore structures, drilling units, TLP’s, and floating SPARs
Please contact our office for more details on the services we perform.