R&D develops Bolt-Check tension measurement tool


R&D, an engineering company headquartered in Denmark that supplies test systems and consultancy for the wind-energy sector, has developed the Bolt-Check system, a bolt-tension measuring tool.

Designed to be used on standard bolts, Bolt-Check offers wind turbine manufacturers and service companies a series of benefits normally only available at much higher prices.

Wind turbines typically contain more than 6,000 bolts, and every bolted joint requires regular in-service tension inspections, because force and vibrations can loosen bolts over time. These inspections are time-consuming and expensive, and results can vary based on the inspection method.

“This Bolt-Check system can be implemented at a cost of 3-4 euros per bolt, which represents a cost advantage for wind-turbine manufacturers since alternative systems using specialized bolts can increase the cost 10 to 50 times per bolt, or even more, depending on the bolt size,” said Flemming Selmer Nielsen, R&D’s senior specialist.

The Bolt-Check system uses its proprietary method based on combining an ultrasonic length measurement with a mechanical measurement, which eliminates the requirement for thousands of bolts to be loosened and then tensioned again to measure the loading on the joints.

Hundreds of bolts can be checked in just a few hours.

“We are offering a solution that gives a high level of accuracy at a very competitive price and even more importantly, it saves a huge amount of time,” Selmer said. “Traditional tools are heavy and potentially dangerous as they operate at high hydraulic pressure,” he said. “Bolt-Check is easy to use and hand-held, therefore, it also provides a significant health, safety, and environment improvement.”

R&D offers Bolt-Check solutions for both new bolts and for bolts already in operation, and includes unique ID tags that are easily added to the bolts either at the installation stage or first inspection check. Tagging the bolt guarantees traceability and detailed documentation.
The system has obtained DNV-GL certification, allowing the Bolt-Check solution to be used for service and maintenance inspections as an alternative to torque or tension tools. The certificate provides independent verification that Bolt-Check fulfils the stringent standards of wind turbine tools and services.

Bolt-Check is scheduled to be presented at the Husum Wind exhibition Sept. 14-17, 2021.

MORE INFO www.rd-as.com/bolt-check