Traditional techniques such as welding, machining and casting can produce turbines as big as a house and it is my job to check they meet our clients’ requirements. On the surface, this is an old-fashioned job but it is one that technology could soon change radically.
Techniques such as 3D modelling and five-axis machining are already making designs more efficient and engineering even more precise. In turn, quality requirements are becoming more stringent, changing the inspection process. For example, checking tolerances on turbine blades used to be done with a metal template. Today, with machines able to work to within a fraction of a millimetre, the checking is done by laser.
Lasers are not the only things that have already changed about quality inspections. My father did a similar job to me. He had to find a payphone if he wanted to call his office, wait days for inspection photos to be printed and use a fax machine to send his report. Today, my smartphone enables me to take hundreds of photos, consult detailed plans and even occasionally broadcast inspections live to my client.
What next? Could virtual reality one day enable us to inspect a turbine without travelling to the factory? Could we be wearing smart personal protective equipment that warns us of any danger as we carry out an inspection? Perhaps, but maybe a more relevant question is: “What will we be inspecting?”
For example, inspecting a casting involves checking for porosity, where bubbles have created voids inside, or shrinkage that might reduce its strength. Will we still be looking for these sorts of defects in ten years’ time? Or will new processes mean checking for entirely different things?
Take a Pelton turbine, for example. This is effectively a wheel with scoops, that is manufactured in one piece. Today these are made using a process that began in the Dark Ages: forging. Soon, they could be 3D printed. After all, rocket parts, and even buildings are being 3D printed, so why not Pelton turbines?
The advent of 3D printed turbines would completely change the list of potential defects to check for, and also the job of the inspector. New sub-contractors that specialise 3D printing could enter the market, so we could also find ourselves visiting different types of facilities in new locations.
Could inspections even become a thing of the past? Smart materials that automatically diagnose problems using embedded electronics raise this prospect. This is clearly a long way off, but just because much of our job involves being immersed in traditional processes, it does not mean we should not look to the future.
This blog has been written by David Tunstall, Quality Surveillance Engineer, WSP
