Infrastructure businesses. Continued positive agriculture market fundamentals are driving demand for our irrigation products and technology solutions as elevated commodity prices, global drought conditions and ongoing food security concerns are all supporting market demand. I am very pleased with our ability to effectively manage our operations to best serve our customers and meet this broad-based demand. Our results further demonstrate the value of our long-term strategy led by sustainable growth initiatives across our businesses, operational excellence and price leadership.”
Kaniewski added, “Reflecting on 2022, our full-year results exceeded the goals we set at the beginning of the year, despite a continued volatile environment, demonstrating the resiliency and relentless focus of our global team. We achieved record net sales of $4.3 billion and delivered record diluted earnings per share of $13.82 on an adjusted basis, an increase of 26.5% year-over-year. We significantly improved return on invested capital through strategic capital allocation and improved working capital performance, which also contributed to a substantial improvement in free cash flow. We continue to profitably grow and perform at a high level, leveraging the strength and sustainability of our Valmont business model. I am extremely proud of our team of more than 11,000 employees around the world and want to congratulate and thank them for their dedication, hard work, and execution. Together, we remain committed to providing our customers with vital infrastructure products and solutions to advance agricultural productivity with an unwavering focus on employee safety and increasing shareholder value."
Fourth Quarter 2022 Segment Review
Infrastructure (67.6% of Net Sales)
Products and solutions to serve the infrastructure markets of utility, renewable energy, lighting, transportation, and telecommunications, and coatings services to preserve metal products
Sales of $771.3 million grew 15.0% year-over-year with double-digit sales growth across all product lines, net of 2.7% unfavorable foreign currency translation impacts. Higher sales were driven by favorable pricing globally, higher volumes, notably in the Lighting and Transportation and Renewable Energy product lines, and sales from the ConcealFab acquisition.
Operating Income improved to $99.6 million or 13.0% of net sales compared to $77.3 million or 11.6% of net sales ($77.8 million or 11.6% adjusted1) in 2021, driven by favorable pricing and higher volumes.
Agriculture (29.4% of Net Sales)
Center pivot and linear irrigation equipment for agricultural markets, including parts and tubular products; advanced technology solutions for precision agriculture
Sales of $335.1 million increased 21.1% year-over-year, with global sales growth led by higher average selling prices of irrigation equipment and higher volumes, primarily driven by continued strength in North America and Brazil, and higher sales of technology products and services.
Operating Income improved to $40.5 million, or 12.2% of net sales ($44.5 million or 13.4% adjusted1) compared to $28.6 million or 10.5% of net sales ($33.0 million or 12.1% adjusted1) in 2021. The benefit of higher average selling prices and additional volume leverage was partially offset by higher SG&A, including incremental R&D expense for technology investments.
Other (3.0% of Net Sales)
Offshore wind energy structures business
Sales of $33.3 million grew 44.1% year-over-year and operating income was $1.4 million compared to an operating loss of $31.3 million in 2021. As previously announced, the divestiture of the offshore wind energy structures business was completed in December 2022.