We continue to invest in AST as the long-term growth opportunities in this segment far outweighed the recent market headwinds. The phased up-fit of our facility in Arizona is on-going and as Eric noted, we are expanding our capacity in Asia. We are well positioned to see a bright future ahead for this segment. Turning to the balance sheet and cash flow, our balance sheet remains very strong. Subsequent to quarter end, in late January, we closed the AMI acquisition using $210 million of cash. Our net leverage ratio, inclusive of the acquisition stands at approximately 2x 2023 adjusted EBITDA. With our reshaped portfolio, we continued to generate substantial cash. Free cash flow in 2023 was over $174 million compared to about $77 million in the prior year.
Working capital management across the company and lower cash taxes were key drivers of cash flow during 2023, in addition to the stellar results in Sealing Technologies. We have strong financial flexibility to execute our strategic initiatives, both organically and through strategic acquisitions that broaden our capabilities. Our goal is to build upon our leading edge positions in markets with secular growth drivers that safeguard critical environments and applications that touch our lives every day. During 2023, we paid a $0.29 per share quarterly dividend, totaling $24.3 million for the year. On February 15, our Board approved another increase to the quarterly dividend to $0.30 per share, representing the ninth consecutive annual dividend increase since we initiated a quarterly dividend in 2015.
Moving now to our 2024 guidance, taking into consideration all the factors that we know currently, we expect total Enpro sales growth to be in the low to mid-single digit range in 2024. We expect adjusted EBITDA to be in the range of $260 million to $280 million and adjusted diluted earnings per share to range from $7 to $7.80 per share. The normalized tax rate used to calculate adjusted diluted earnings per share remains at 25% and fully diluted shares outstanding are approximately $21 million. Capital expenditures are expected to be approximately $60 million or around 5% of sales in 2024 as we continue to invest in compelling future growth opportunities across the company. Two-third of this capital spending for 2024 will be in support of growth investments on focused leading-edge platforms in the Advanced Surface Technologies segment.
In AST, we expect continued demand in the first half – excuse me, we expect continued demand weakness in the first half of 2024 after seeing sequential improvement in AST in the fourth quarter of last year, based on current backlog in order patterns, we anticipate results to decline sequentially in the first quarter of this year. We believe the first quarter will represent the bottom of the semiconductor decline for our business, with adjusted EBITDA of about 5% to 10% below Q3 of last year. Capital spending typically lags unit growth after a trough and approximately two-third of our semi sales are driven by equipment builds with the remaining one-third tied to wafer production. We are well positioned when capacity utilization improves and capital spending recovers.
In the Sealing Technologies segment, we anticipate normal seasonality to return this year resulting in incrementally stronger first half of the year compared to the second. The largest portion of segment revenue follows trends in global industrial production and North American commercial vehicle production, although we have growing exposure to faster-growing markets, such as aerospace and space, sustainable power generation and pharma. As Eric noted, the acquisition of AMI will be accretive to Sealing’s results, both in the coming year and longer term. In commercial vehicle, the sharp decline in OEM demand anticipated this year is expected to be partially offset by improved aftermarket mix and new product advancements as the year progresses.
According to industry forecasts Commercial vehicle trailer builds are expected to decline 25% in 2024. As a reminder, approximately one-third of our commercial vehicle market — our commercial vehicle business is tied to OEM trailer builds with the balance serving the aftermarket. Also of note for the Sealing segment, in 2024, we expect a smaller impact from strategic pricing initiatives compared to 2023. We have made progress over the past several years optimizing and repositioning the Sealing Technologies segment, resulting in significant improvements in the composition and profitability of the segment. We’re well positioned currently and we’ll continue to invest in various pockets of growth while focusing on broadening the segment’s capabilities with selecting organic moves overtime.
We believe the timing of the upturn in our semiconductor business and to a lesser degree, the magnitude of the decline in commercial vehicle trailer builds, as well as trends in global industrial production will be the primary swing factors driving our performance in 2024. The mid to high end of our guidance range reflects a robust second half recovery in our semiconductor business, while the lower end reflects the possibility of the uptick happening later. Regardless of the precise timing, we are well positioned for the widely expected upturn, and we are making the appropriate investments to drive future growth and value. Now I’ll turn the call back to Eric for a few closing comments.
Eric Vaillancourt: Thanks, Milt. We continue to demonstrate our best-in-class balance portfolio that generates attractive margins and cash flow returns in a variety of economic environments. Our value-creating strategy remains unchanged, and we continue to invest where we are the strongest, while considering strategic acquisitions that build upon our leading edge capabilities. I would like to recognize the hard work of all of our colleagues across the company as we continue to differentiate ourselves in a disciplined and consistent fashion. Thank you for joining us today. We appreciate your interest in Enpro. We’ll open the line to questions.
Operator: [Operator Instructions]. Our first questions come from the line of Jeff Hammond with KeyBanc Capital Markets. Please proceed with your question.
Jeff Hammond: Hey, good morning, everyone. Congrats welcome aboard Joe, and congrats, Milt It sounds like we might hear from you one more time.
Milt Childress: Yes, I think that will be the case. I’ll be in the room next quarter.
