Non-destructive testing for SMEs.

Working with metal is fantastic. However, the stakes are often high. For example, a bad weld can result in huge repair costs and problems detected too late can jeopardize the delivery of a project. To prevent such problems, NDT-Netherlands performs various forms of non-destructive testing especially for Dutch SMEs. Ultrasonic bolt stress testing is one of them. 

Ultrasonic bolt stress testing delivers the necessary gains. That's what director/owner Wolter van der Zee says on behalf of NDO-Nederland, part of Inspecto Visio from Sneek. "The big advantage of such an examination is that no bolts and nuts are broken. In addition, you can be sure that they are all tightened neatly. Furthermore, we store all measurement data, so you can also check whether nuts and/or bolts have loosened over time due to use." 

Reliable measurement result

In contrast to many other methods, NDT's ultrasonic bolt stress testing is carried out during the tightening process. This is precisely why, if necessary, immediate action can be taken and achieving exactly the right preload becomes child's play. "Moreover, our measurements are not affected by the coefficient of friction of the thread," Wolter adds. "As a result, you are always guaranteed a reliable measurement result. At the same time, it allows you to investigate which lubricant works best, so that tools last longer and costs are saved." 

Custom

During ultrasonic bolt stress testing, NDO-Netherlands deploys first-class measuring equipment that has been optimized together with the manufacturer especially for this purpose of use. "We also contributed around the design of the probe and a so-called shutoff box was developed by us in-house," Wolter says. "The result is a method that assures the customer that the bolts in his construction are tightened with exactly the right preload. This not only prevents expensive repairs afterwards. Because the preload is immediately visible during tightening, adjustments can also be made immediately as needed."

Preload

During clamping, NDO-Netherlands uses ultrasound to determine the exact preload (a crucial factor for the nuts and bolts used in a structure). As soon as it is approached, the shutoff box causes the tightening tool to rotate more slowly. Once the preload is achieved, the pump stops. "We can perform the ultrasonic bolt tensioning examination during both the installation and maintenance phases and on any bolted joint applied," Wolter concludes by emphasizing the versatility of the special examination method.