The Centre of Excellence is now the world's most advanced facility for specialist fluid-filled motor manufacturing.
The "fit-for-nuclear" facility will support the group's long-term growth plans across its international markets.
Commenting on the event, chief executive Ewan Lloyd-Baker said: "It was a great pleasure to host the Duke and Duchess to officially open the facility.
"It was a pleasure to have so many of our customers and other stakeholders witness the Royal visit, and see the outcome of all the hard work we have delivered over the past few years.
“We were proud to showcase the new facility to our strategic partners and loyal customers who will benefit from our enhanced capabilities."
The unveiling also saw the Duke and Duchess present the firm with its recent Queen's Award for Enterprise: International Trade.
HTG services the power, oil and gas, nuclear, process, renewables and marine markets via its 500 strong workforce, from seven sites strategically located across the globe.
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