Jul 25, 2014French technology-based tracking solutions company Beweis has developed an RFID-enabled system for verifying that pipes have been properly welded at nuclear power plants and petrochemical facilities, and for tracking the soundness of those welds via radiographic images. The company's solution is being tested by the French government's PACA Labs, as part of what is known as the Be-Tag project, financed by the federal agency Risk Division, with consulting services provided by the Institute of Welding Group, the French National RFID Center and the City of Martigues. The test, being conducted at a nuclear energy plant operated by Areva, consists of attaching passive EPC Gen 2 ultrahigh-frequency (UHF) RFID tags to pipe welds and to radiographic images taken of those welds, in order to prove that the welds are without flaws when pipes are being installed at sites for which integrity is critical. The weld and image tags are interrogated in the field to better identify each weld, and to confirm which image matches a particular weld.
Beweis provides its RFID technology to the military sector, as well as to the automotive and other manufacturing industries, according to Sylvain Crozet, Beweis' technical director. Throughout the past year, Be-Tag—which the company refers to as a weld anti-counterfeiting system—was developed for use on pipe welds, to link a particular welded pipe joint with data regarding the inspection, including the radiographic imaging data, the time of the weld and the location of physical radiographic film of that weld. In that way, users not only can accurately locate a particular weld, but also authenticate the identity of that pipe and welding.
As pipes are laid for the construction of a new or expanded facility, a welder joins them together onsite. Each weld is then tested via radiography to ensure its integrity, says Romain Knezevic, Beweis' software engineer, and an image is taken. Without an RFID tag to identify that pipe weld, a worker typically marks the weld via a lead plate, on which a serial number is stamped.
If a pipe is not properly welded, it poses a risk of rupture—which is of extreme concern during the movement of highly toxic or volatile liquids. To better identify each weld's integrity, radiographic images in a view bundle (a bundle of the films created by the radiography) are stored in an envelope that protects it from light and dust.
With Be-Tag, an RFID tag containing an Alien Technology Higgs-3 chip is strapped to the welded section of pipe, and the tag's unique ID number is linked in Beweis' software to information about the weld, including the date, the welder's name and the pipe's diameter. To accomplish this task, welders carry a Motorola Solutions Psion Workabout Pro 3 handheld computer to read the tag and input necessary data. The location information, based on GPS data derived from the handheld, is also stored in the software, as well as on the tag itself.
The software resides on a local server hosted by the end user—which, in the case of the pilot, is Areva. Authorized users, including inspectors and film developers, can then access that information.
Once the weld is completed and the tag is attached, the radiographic images are taken and the tag's unique ID number (known as the Secret ID) is printed on a unique, non-RFID paper label, known as a view-label. The label is then attached to that bundle.
Upon receiving the view bundle and the unique ID number at his or her office, the film developer generates an RFID-tagged label and attaches it to each piece of film within that bundle. Every film label's tag ID number is stored in the software, along with the other data related to that weld. According to Crozet, the RFID labels are durable enough to survive the film-developing process.
The developed film is then analyzed, with the results stored on the server. After analyzing the radiographic films, the inspector can then update data in the system to record that the weld has been approved.
The system is intended to provide an automated link between the weld itself (and its location) with the physical radiographic images of that weld, as well as the office in which those images are being stored. A worker in the field could then use the handheld reader to confirm the connection between a specific weld and the physical image file, enabling an inspector or other employee to update information in the software as necessary.
The system also prevents those photographing images of the welds in the field from cheating or committing fraud, Knezevic adds. The concern, he explains, is that if a specific weld is difficult to capture in a digital image, the operator may shoot a different weld that is easier to photograph, then claim that the picture corresponds with the other weld. To prevent this from happening, Beweis places two brass squares, with a letter of the alphabet cut into each one, inside the pipe tag. The letters are invisible to the human eye, since they are sealed inside the tag's plastic casing, but will be discernible on radiographic images once the film is developed. Therefore, at the time that the weld images are examined, the two letters can be compared against those expected for that particular tag ID number, thereby confirming whether the picture is authentic.
The RFID tags in the film labels enable personnel not only to identify the radiographic images during development and inspection, but also to identify them after they have been archived, and to quickly link them to data regarding the weld. For the trial, staff members are using a CAEN RFID desktop reader to interrogate the labels, though Beweis also works with other reader vendors, Knezevic notes.
The system is intended to reduce the incidence of errors that could result from manually writing ID numbers on paperwork, or from the application of lead-based number plates on welds. These lead-based numbers can pose a risk to workers' health (since lead can be toxic), as well as making their work slower than it would be simply using RFID to collect and store data.
During the pilot, which is slated to begin later this summer, the tags will be used only to identify welds during the construction process, after which they will be removed. However, Crozet says, some of the company's other clients "are thinking about keeping the tag attached to the welds after the end of the construction." In that case, he says, "Be-Tag is a convenient and reliable way to identify welds—for example, during maintenance—during their whole life," which can extend to approximately 40 years.
