Blackstone has agreed to acquire Flow Control Holdings, a maker of stainless-steel fittings, valves, hoses and fabricated assemblies, from Audax Private Equity. Audax will retain a minority equity stake in the business in partnership with Blackstone.
Audax bought Flow Control Holdings (FCH) in 2022 as a supplier of sanitary fittings to dairies and drug plants. It added ten businesses over four years and built a dedicated data center division on top of the machining and fabrication base it already had.
FCH does not build cooling systems. It makes the hardware they are assembled from — precision stainless fittings, valves, strainers, coolant hoses and custom-fabricated assemblies — and sells it to the equipment makers, system integrators and hyperscale operators who install the finished equipment. It also supplies comparable hardware to food, beverage and pharmaceutical plants.
A data center cooling system removes the heat created by servers and carries it outside the building. In a liquid-cooled system, chilled liquid is pumped to the server racks, where it absorbs heat from the processors and other equipment. The warmed liquid then flows back to a cooling unit, which transfers that heat to the building’s cooling system. The liquid is cooled and pumped back to the servers, repeating the cycle. FCH makes hardware at nearly every step of that chain.
FCH operates through Steel & O’Brien, Ace Sanitary and Strahman Group, along with a dedicated Data Cooling division. Steel & O’Brien makes stainless-steel fittings and fabricated assemblies; Ace Sanitary makes hoses and tubing; and Strahman produces washdown equipment, pumps and process valves. The Data Cooling division brings those capabilities together for liquid-cooled data centers. FCH, led by CEO Scott Kerns, is headquartered in Cincinnati.
“We believe that FCH has enormous tailwinds for continued growth as the latest generations of high-performance AI infrastructure increasingly rely on liquid cooling technology for significantly improved energy and chip efficiency,” said Bilal Khan, a senior managing director at Blackstone, and Mark Zhu, a managing director at the firm, in a joint statement.
The Edgewater Funds formed FCH in November 2018 with JZ Capital Partners and industry executive Phil Pejovich. During its ownership, FCH acquired Steel & O’Brien, a New York-based maker of sanitary stainless-steel fittings and valves (November 2018); Top Line Process Equipment, a Pennsylvania-based maker of sanitary pumps, valves and fittings (August 2020); Ace Sanitary, an Ohio-based maker of sanitary and high-purity hoses (February 2021); and FlexFit Hose, a Maryland-based maker of flexible hose for sanitary and high-purity applications (June 2021). Edgewater agreed to sell FCH to Audax in March 2022 and closed the sale that April.
Under Audax, FCH continued to build through add-ons. These included Andron Stainless, a South Carolina-based maker of sanitary stainless-steel fittings, valves and tubing with an operation in Ontario (January 2023); DSO Fluid Handling, a New Jersey-based supplier of sanitary aftermarket parts, and Flowtrend, a Texas-based supplier of sanitary pump and valve parts (February 2023); and the US assets of Ultibend Industries, a New Zealand-based maker of sanitary stainless-steel fittings with a California fulfillment center (March 2023).
FCH added Strahman Holdings, a Pennsylvania-based maker of washdown equipment and process valves (June 2023). The pace paused through 2024 and resumed alongside the move into data center cooling. FCH acquired Precision Stainless, a Minnesota-based maker of stainless tube and sanitary buttweld fittings (May 2025); Gemco Valve, a New Jersey-based maker of spherical disc valves for powders and dry bulk materials, which went into the Strahman Group division (August 2025); Advance Fittings, a Wisconsin-based maker of stainless fittings and components (September 2025); Axiflow Technologies, a maker of sanitary twin-screw pumps (February 2026); and Sanitary Solutions Group, a supplier of sanitary stainless-steel tubing, fittings and valves (April 2026).
Data center cooling system technologies have evolved greatly over the past ten years. A server rack drew about 5 kilowatts a decade ago and the worldwide average reached 7.6 kilowatts in 2025, according to the Uptime Institute, but racks built for artificial intelligence workloads run at 60 to 120 kilowatts, and hyperscale facilities now support more than 135 kilowatts. Dell’Oro Group projects that thermal design power for graphics processors at the frontier will pass 4,000 watts by 2029.
Air stops being practical somewhere in the 30 to 50 kilowatt range. According to Nvidia, air would have to be chilled below freezing or moved at near-gale speed to carry away the heat of a modern server rack. By volume, liquid carries roughly 3,500x the heat of air. Dell’Oro sizes the data center liquid cooling market at roughly $3 billion in 2025 and approaching $7 billion by 2029.
Blackstone (NYSE: BX), headquartered in New York City, manages approximately $1.35 trillion in assets across private equity, real estate, public debt and equity, non-investment grade credit, real assets, and secondary funds. The firm also provides financial advisory services, including financial and strategic advisory, restructuring and reorganization advisory, and fund placement services.
Blackstone’s investment in FCH is through two strategies – Blackstone Capital Partners and Blackstone Energy Transition Partners. FCH is the second data center thermal management business the energy transition vehicle has backed in the past six months. In March 2026 it agreed to buy a majority of Advanced Cooling Technologies, a Pennsylvania maker of heat pipes, vapor chambers and liquid cold plates. Advanced Cooling builds finished thermal hardware; FCH supplies components that go into it.
Audax Private Equity invests through a flagship strategy targeting companies with EBITDA of $20 million to $100 million and enterprise values of $200 million to $1.0 billion, and an Origins strategy for businesses with EBITDA of $5 million to $20 million. Sectors of interest include business services, financial services, healthcare, industrial services and technologies, and software and technology. Audax has invested in more than 180 platforms and over 1,500 add-ons since 1999, completed more than 100 add-ons in 2025 alone, and ranked sixth among US private equity acquirers by deal count that year.
“We view the FCH investment as a text-book example of Audax’s ability to build strategic assets through disciplined execution of the Audax Value Agenda and Buy & Build approach,” said Don Bramley, a partner at Audax Private Equity.
Audax closed its seventh flagship fund at a $5.25 billion hard cap in July 2023 alongside $1.8 billion of general partner co-investment capital, and Origins Fund I at $774 million. Audax was founded in 1999 by Geoffrey Rehnert and Marc Wolpow and is headquartered in Boston, with approximately $20 billion under management as of July 2026.
Houlihan Lokey and Jefferies were the financial advisors to Flow Control Holdings. William Blair, UBS and Goldman Sachs were the financial advisors to Blackstone.
The transaction is expected to close in the fourth quarter.