Eddy Current Testing Services in Tampa

Eddy current testing services near Tampa: tube bundles, coated welds and insulated lines

Around Tampa, most eddy current testing is tube work. Condenser and exchanger bundles at the power and fertilizer plants are tested during outages so plugging decisions can be made tube by tube. The method is also used on painted welds in ship repair and, in its pulsed form, to screen insulated piping. Houston-based Atlantis plans each campaign from the tube list, under procedures approved by an ASNT NDT Level III.

Big Bend's reused condenser. Tampa Electric repowered Big Bend at Apollo Beach as a 2x2x1 combined-cycle plant. The existing Unit 1 steam turbine was rebuilt, the existing condenser and circulating water system were refurbished and kept, and the water intake was modified for the Clean Water Act 316(b) rule. A reused condenser brings its tube history into the new plant, so each outage's eddy current data is compared with earlier campaigns. A typical condenser campaign includes:

• bobbin-coil screening of the full bundle;
• rotating or array probes on the tubes that show indications;
• a plugging map that the owner can act on before the unit returns to service.

Inlet-end erosion, pitting and wear at the support plates are the findings that most often decide which tubes are plugged.

Process exchangers and tube material. At Mosaic's Riverview complex, the acid units and the auxiliary steam boiler are the kind of plant where exchanger bundles come in a range of materials, and the material decides the method. Conventional eddy current suits non-ferrous and austenitic tubes. Carbon steel tubes respond poorly to conventional coils; for them, IRIS tube inspection measures the wall ultrasonically, one tube at a time. When a bundle mixes materials or has been retubed, the tube sheet map has to show which tubes are which before probes are chosen.

Coated welds and insulated piping. Eddy current can find surface-breaking cracks through paint, which saves blasting and recoating on ship structure at the yards and on cranes and steelwork at the port. Where crack depth on a coated weld matters, ACFM is the related electromagnetic method that also sizes the crack. Insulated lines at a humid coastal site are prone to corrosion under insulation. Pulsed eddy current reads the average wall under the insulation and cladding with both left in place, so insulation is opened for UT only where the readings are low.

Planning a tube campaign. The quote is built from the tube material, outside diameter, wall thickness, length and count for each bundle, plus whether the tubes are straight or U-bend and the date the bundle will be clean and open. Calibration standards are made from tube of the same material and size, so order tube for the standards early when a bundle is non-standard. Report requirements, such as the plugging criteria and whether the owner wants the raw data files, should be agreed before the crew arrives.

Looking for eddy current testing companies? The national service, including what tube inspection reports contain, is on eddy current testing services. To learn the method, see ET Level II training and the eddy current simulator. Send the Tampa tube list or bundle drawing with the outage dates.