Heat Exchanger Tube Inspection Simulator: ET, IRIS, Remote Field and MFL
The heat exchanger is the second dedicated installation in Atlantis Practical NDT: a bundle of 2,000 tubes for eddy current, IRIS, remote field and MFL tube inspection. Tube inspection is a test of procedure and stamina, the same set-up and calibration held steady across hundreds of tubes, with interpretation that decides which tubes stay in service. That makes it a good fit for repeated practice.
IRIS jobs: centring and dropouts
IRIS, the internal rotary inspection system, measures tube wall with ultrasound reflected from a rotating mirror inside a water-filled tube. In the 8 IRIS jobs the trainee centres the probe in the tube and scans. The simulator computes the water and steel sound paths and the signal dropouts that eccentricity and bubbles cause, which are the two faults that spoil real IRIS data: a probe that is not centred and air in the water column.
Eddy current tube jobs
Eddy current tube inspection uses the bobbin technique: an encircling probe pulled through each tube after nulling on the reference. The response is computed from skin depth, lift-off, phase and gain, so frequency choice and a careful null show up in every tube that follows. The heat exchanger eddy current model is not a validated probability-of-detection model; use it for technique, calibration and signal reading, not to estimate what a real bundle would show. See the eddy current simulator for the other techniques.
Remote field, MFL and choosing a technique
Remote field and MFL tube inspection are part of the same installation. The choice between techniques is mostly about the tube material: bobbin eddy current suits non-ferromagnetic tubes, remote field and MFL are used on ferromagnetic tubes where conventional eddy current struggles, and IRIS gives a direct ultrasonic wall measurement where a quantitative answer is needed. Practising them side by side on one bundle is how a technician learns why a tube campaign is planned around the tube material, not around the technician's favourite method.
What tube inspection is looking for
Exchanger and boiler tubes lose wall from the inside and the outside, wear where they pass through support plates, pit, and crack. A tube campaign is usually run inside a shutdown window, so the technician's ability to keep the same calibration, probe speed and recording discipline from the first tube to the last is what decides the quality of the data. In the simulator, a campaign can be practised at the guided level and then repeated independently until the routine holds.
What a tube practical records
The learner record lists the pinned revisions, the equipment, the settings, the calibration values, the checks and each observation with its coordinates. For a tube practical that is the evidence an instructor needs to see whether the null, the frequency and the recording discipline held steady across the bundle, and where the interpretation went wrong, without having watched every tube being inspected.
What the tube jobs reference
The jobs follow the twelve-step training procedure with pinned revisions of the bundle, the procedure and the equipment. Plugging decisions and acceptance on a real exchanger belong to the owner's programme; the training report states that code acceptance is not evaluated and that interpretation requires instructor review.
What a virtual bundle cannot reproduce
Tube cleaning before inspection, the water supply for IRIS, pulling a probe through a long, fouled tube, real deposits and real noise are not on a screen. Neither is the physical effort of a long campaign. The simulator builds the procedure and the signal-reading habits; real tubes and real data are still needed before a technician reports on a real bundle.
Frequently asked questions
Which tube inspection techniques are in the heat exchanger?
Eddy current, IRIS, remote field and MFL tube inspection, on a bundle of 2,000 tubes.
Why does the IRIS signal drop out?
Because the probe is not centred in the tube or there are bubbles in the water column. The simulator computes both effects so you can practise avoiding them.
Is the heat exchanger model a probability-of-detection model?
No. The eddy current heat exchanger model is not a validated probability-of-detection model; it is for practising technique and signal reading.
Next steps
Practical NDT is a training simulation, not a validated engineering tool. It runs in a standard browser, works offline once downloaded, extends to standalone headsets and is integrated with the Atlantis LMS and ERP, so learners reach it from the client portal with one sign-in. Practice in it does not replace the practical examination or the experience hours your written practice requires.
Speak to an ASNT NDT Level III
Discuss your inspection requirements with Atlantis NDT. Include the asset, method, location and documents you need reviewed.