Visual inspection of structural welds has long been a costly and intrusive process. Bob Ward, an expert in ultrasonic testing and electromagnetics innovation at GE Measurement and Control,discusses how a new generation of weld-inspection equipment is now changing the equation - with highly reduced downtime, fewer false calls and no introduction of toxic materials into the environment.
Imagine that you are a hundred metres above the roiling surface of the North Sea, suspended by ropes. Working on the massive crane that is the heart of the drilling platform - clipboard in hand, whipped by the winds - you struggle to complete a visual inspection of welds or record your findings. The entire rig is out of service while you perform your tasks, and, even after your inspection is complete, the crane will need to be repainted before operations can resume.
"This costs the oil company millions of dollars a day in lost production - sometimes tens of millions," says Bob Ward of GE Measurement and Control. "And then you have the environmental impact of using chemical agents to strip the paint down to bare metal before the inspection can even start, and these end up in the seawater below."
The real shame, Ward says, is that there is no reason at all to strip the paint in the first place: weld inspection using eddy-current (EC) test equipment is fully accurate even through painted surfaces. In fact, GE's newly introduced Mentor electromagnetic (EM) system now features automatic compensation for varying paint thickness in its digital record of test results. And this is just one of many enhancements the system brings to the weld-inspection technician's job.
"Mentor EM is a quantum leap over all previous weld-inspection technologies - whether eddy current, ultrasound or radiological," says Ward. "The device is designed from the ground up to bring a new level of efficiency and accuracy to the test procedure."
As is clear from the oil platform scenario above, weld inspection and testing are often performed in physical conditions that are far more challenging than a laboratory setting. Making matters worse, technicians have had to rely on printed materials such as service bulletins or manual instructions to take them through each step of the inspection process. This approach was fraught with opportunity for errors, to the degree that a second technician was often called upon to review the work of the first - a costly and time-consuming process that, in and of itself, could introduce errors into the results.
"GE Mentor EM eliminates the paper trail that has always been part of EM eddy-current testing," says Ward. "Using Mentor Create software, the test procedure is built for the instrument's digital display. The technician is able to focus 100% on the task, simply stepping through each screen on the handheld Mentor EM unit as the test proceeds."
In addition, as accurate digital reports capture exact test results, there is little need for a senior-level technician to be physically on site to assess the results of the inspection.
Furthermore, the GE Mentor EM uses modern computer technology not available in portable EM testing devices. Its high-resolution display is easy to see in any light, the touch screen is designed to work with gloved hands, and the interface allows technicians of all levels to easily communicate with one another.
Importantly, the test equipment gives technicians instant access to a wealth of information and support via built-in networking, letting them immediately review up-to-date procedures and workflows directly from the device. In addition, Mentor EM lets on-site technicians collaborate with level-3 experts in real time as needed.
This is particularly meaningful in light of the industry's skills shortage. A smaller staff of senior personnel can ply their expertise - validating technician findings and distinguishing false calls - from a remote location, rather than climbing the structure for a first-hand look. Not only is it a vastly more efficient process, but the on-site technicians are also freed to raise and resolve issues without the fear of shutting down operations because of a false call.
Ward notes that the Mentor EM device has some additional appeal for more junior technicians. "Young people entering the field have grown up with digital technology in every aspect of their lives," he says. "The modern look and feel of the Mentor EM has much more credibility with them as a state-of-the-art device than the devices emulating analogue-signal processing units, with their old-school dials and buttons."
GE's newly introduced Mentor EM eddy-current inspection system offers the latest technology, capable of taking the inspection of welds to a whole new level of productivity. Not only is it among the most advanced diagnostic EC technologies available, but the new Mentor EM also packages the system and interface in a modern and intuitive handheld device for test technicians, ensuring accurate and reliable results.
Leveraging innovative Mentor Create software, manufacturers and service providers can create customisable, on-device inspection workflow applications that provide consistent, up-to-date and easy-to-follow instructions for technicians of all levels. Inspection technicians gain easy access to on-device photos, maps, procedures and videos for reference while setting up, or acquiring or analysing data.
The Mentor EM application-specific user interface makes it possible to automate a wide range of specialised and custom test situations. By placing workflows directly on the device, Mentor EM helps to ensure strict compliance with codes, guidelines and standard practices. Depending on skill level, operators can choose to use the device in 'expert mode' or 'workflow-on-device mode'. By limiting the range of adjustments available to the operator, the opportunity for error is substantially minimised.
In an ideal world, facility operators should never have to choose between safety and uptime. With the introduction of Mentor EM and Mentor Create, GE has taken a major stride toward enabling offshore rigs and other painted mechanical structures to function more safely and efficiently than ever before.