The deal - sealed in the presence of the First Minister Carwyn Jones on Monday evening in San Francisco - will see unique products that have been developed and patented in Wales deployed across the United States market.
The First Minister, who is leading a trade mission to the region, congratulated both companies and said:
"The Welsh Government is delighted to have worked closely with Hydro Industries in Wales and will continue to support them in their joint venture with T&T Salvage and their continued growth as a company in Wales.
"I welcome this new venture involving two companies that between them have the potential to bring about real environmental benefits through mitigating the damaging effects of disasters, whether they be natural or man-made.
"This agreement today will not only launch Hydro into the US emergency response arena – a truly significant market - but will also generate a good number of high quality jobs in Wales."
Hydro Industries, based in Llangennech, is a high-tech company specialising in the design, manufacture and operation of electro-based water treatment products.
The company will be supplying some of their highly specialised patent protected products to T&T Salvage and undertake research and development of new bespoke products for T&T Salvage.
T&T Salvage operates one of the most extensive response networks in the world. Positioned throughout the United States and its territories, T&T Salvage owns and maintains fast response fire fighting systems, inert gas generators, nitrogen generators, ship-to-ship (STS) pumping and lightering systems and diving systems, all transportable by air.
Wayne Preece CEO of Hydro Industries said:
"The joint-venture is a genuinely exciting and innovative collaboration. We’ve established ourselves in a short time as leaders and innovators in environmental marine technology and it is a great privilege to work side by side with a market giant such as T&T.
"This new relationship provides a great opportunity to strengthen and develop our technological capabilities and grow the business. We are delighted that Hydro Industries is leading the way in forging global networks in an area that is so important to the future of us all.
"During the next three years, this project will create high quality job opportunities for an estimated one hundred people, not only within Wales but for Welsh people who have an ambition to work outside the UK in exciting and diverse locations."
Mauricio Garrido, President of T&T Salvage said:
"Essentially what we have here is the fusion of an innovative technological team with an expert, experienced, specialised unit. T&T is simply one of the worlds’ largest and most successful salvage companies and Hydro will help T&T achieve a technological edge in environmental protection."