This proprietary eddy current and diameter measurement device has been in use for more than 20 years. The eddy current probes were developed by FOERSTER specifically to test reformer tubes with FULL penetration up to 23mm and all alloys. Unlike standard eddy current systems, these powerful probes generate a magnetic field strong enough to completely penetrate the tube material. The most important requirement for testing these tubes is the need to look inside the tube wall for the formation of micro-fissures and cracks. As the EC probes do not require a couplant and operate electronically, the readings obtained are completely repeatable from test to test. The diameter measurement is accomplished simultaneously using up to four lasers depending on tube to tube clearances.The lasers allow for maximum accuracy and repeatability. Diameter measurement of tubes is used as a secondary procedure revealing normal creep and also clarifying the probable conditions that caused damage. Cracks can form without diametric growth. There can also be significant diametric growth without cracking. These conditions are generally caused by operational upsets.

The complete system is mounted on a unique tube crawler designed and built by MP. The special design of the crawler allows for passage from the furnace roof to the floor, passing below any flue gas collection tunnels. The probes and lasers are mounted near the bottom of the crawler allowing readings to be taken in the most critical lower areas of down flow steam methane reformers. The device is also designed to test reformers with small tube to tube clearances down to 20mm. This allows the inspection of furnace designs with very tight clearances from the OD. Other configurations are available to test up flow reformers. Tubes are inspected in less than two minutes each. No cleaning of the tubes is required.

The MIDREX Direct Reduction Process converts iron ore into a high-purity product for use in steel making, iron making and foundry applications. The process flow is upward. The tubes have diameters between eight and twelve inches.For crack inspection, the reliable FOERSTER developed eddy current technique is used. Cleaning of the tubes due to greater amount of scale on the tube surfaces is not required. Integrated multi laser devices accurately measure tube creep, which can be 10% or more of the tube diameter.The mechanical and electrical components of the mechanized inspection system are especially designed for the inspection of the MIDREX tubes which considers process flow direction, scaling, dual alloys and large diameters. One tube can be accurately inspected in less than two minutes.

A new sophisticated inspection device has been developed by MP and is available for use. It has proven to be rugged and reliable in actual critical field service. A powerful laser unit allows measurement of the tube ID with a high level of accuracy. This tool was developed for those furnaces that may require creep values registered below the floor, have tubes that are touching and can not be fully inspected from the OD, or simply to use the access to the inside for testing when it is available as a secondary confirmation of tube creep condition.The results show the tube diameter through 360° and in a 3-dimensional view. This information can be shown for single tubes, single rows or for the entire reformer. ID laser testing takes less than two minutes per tube.

Outlet pigtails are critical areas which need closer inspection due to their location and designed function. For the detection and the evaluation of tube expansions FOERSTER has developed a unique device to measure pigtails diametrically from the tube outlet to the manifold.These measurements are performed on two axes. This configuration enables the evaluation of the diametrical growth of both the straight pigtail sections and the bends with their diametrical differences due to the bending process. As compared to manual gauge testing this new system is very fast, reliable, repeatable and provides an accurate diameter profile over the complete length of the pigtail.

Magnetische Prüfanlagen and U. S. Thermal Technology are proud to introduce TUBELIFE, the new state-of-the-art probabilistic tube life assessment software. This program, combined with our advanced inspection-capability, provides integrated reformer asset management to the refining and petrochemical industries.This software utilizes customized stress analysis, proprietary creep models, and heat flux and skin temperature profiles for different reformer designs and burner configurations to calculate the cumulative probability of catalyst tube failure over time. Inspection results are taken into account in the output of the program. Future operational conditions can be added and modeled to observe the possible effects. This tool enables the industry to achieve a lower risk of failures and unplanned plant outages and also allows for an optimized spares strategy

Several furnace designs utilize a dissimilar weld to connect the inlet assembly to the reformer tube. In some cases this has led to cracking in the heat affected zone of the weld on the lower alloy side. FOERSTER has developed a customized testing device and procedure for testing these welds in some furnaces. Procedures can be adapted for many furnace designs. This is an ultrasonic test incorporating special devices to assurecomplete coupling and accurate probe manipulation from the ID. Cracks are detected and sized allowing the continued safe operation of the furnace.