Serge Boutry spent 42 years building a compressed air empire. Two rounds of PE deals later, he was gone.

Serge Boutry spent 42 years building a compressed air empire. Two rounds of PE deals later, he was gone.

When Rubix announced the acquisition of Airflux on December 17, 2025, the press release was four paragraphs. No deal value. No mention of Serge Boutry.

Boutry founded Airflux. 1983, Lille, 148 rue de Marquillies. I found that address later on Pappers, the French corporate registry platform. It's still Airflux's registered address today. He started out as a salesman selling compressors to small factories in northern France, and he did it for forty-two years. By the time Rubix came knocking, Airflux was a nationwide operation: $52 million in annual revenue, 24 branches, 2,000 maintenance contracts under management, 80 technicians who promised to be on-site within two hours. In the French compressed air business, the number of companies that had achieved national coverage without depending on any single OEM was one. This was it.

Boutry's name did not appear once in the Rubix press release. The name on the signature was Verstraete.

I wanted to figure out what happened in between.

The first lead came from a French M&A platform called Fusacq. In 2014, Airflux did a round of equity financing, bringing in Nord Capital Partenaires and CM-CIC Capital Finance. A FIP fund managed by Turenne Capital also came in for a piece. The original text was in French. Boutry, signing as "Président," said Airflux would keep growing through acquisitions across France and push into international markets. That year Airflux had about 170 people, 22 branches, $37 million in revenue.

Nord Capital and CM-CIC are both regional French PE funds. Not global monsters like Advent, but the logic is the same: get in, help you speed up, get out a few years later. For Boutry, this was probably the best deal he could get. Airflux had grown to a size where doing more acquisitions on its own cash flow was getting hard. Outside capital was the accelerator. The price was that from that moment on, the clock was no longer entirely Boutry's to set.

Three years later, in 2017, Airflux made a move that changed everything: it acquired Chaumeca. Chaumeca wasn't a distributor. It was a manufacturer. Dryers, filtration systems, heat exchangers. This deal turned Airflux from a pure channel player into a solution provider with its own manufacturing capabilities. Chaumeca's general manager Rémy Rochard joined the Airflux leadership. On Crédit Mutuel Equity's website, there's a dedicated page about Airflux, and it doesn't mince words: Rochard was set up as Boutry's successor. The original French reads "le successeur du fondateur."

Then there was no then.

I couldn't find Boutry anywhere in the public record after that. Couldn't find when he left Airflux's management. Couldn't find a departure statement. Couldn't find a single word from anyone thanking him for forty-two years. Same for Rochard. The man formally designated as successor was also absent from the Rubix acquisition announcement. By the end of 2025, the person standing in front of Airflux was Verstraete, a name with almost no public footprint before this.

There was one more record on Pappers I nearly scrolled past.

On its own, this record is nothing special. Put it on the timeline and it gets interesting. 2014: bring in PE capital. 2017: acquire Chaumeca to boost revenue and gross margin. 2018: strip out the unrelated CNG business to clean up the financials. Then the founder and his designated successor fade out one after the other, a new CEO is brought in, and the whole thing gets sold to a bigger platform.

You'll find this playbook in any textbook on mid-market PE exits. Except the textbooks are usually talking about software companies or restaurant chains, not compressed air distributors.

The Rubix side of the story is something I don't think most people have looked at closely either.

Advent International bought the UK's Brammer and France's IPH Group between 2016 and 2017 and bolted them together into Rubix. PE funds typically run on a 7-to-10-year cycle. 2025 is year eight.

Three things happened in November 2025. Same month.

Rubix closed the acquisition of ERIKS UK & Ireland. ERIKS does valves, seals, hoses. The deal pushed Rubix's UK and Ireland revenue past $890 million in one shot. Same month, Rubix sold minority stakes to a string of institutional investors: Neuberger Berman Private Markets led, followed by Adams Street Partners, LGT Capital Partners, J. Safra Sarasin, BlackRock. Same month, the CEO was swapped out.

The first two together point in one direction. Do a big acquisition to push revenue up one more notch, then sell minority equity to a bunch of name-brand institutional investors to set a price. That's exit prep. BlackRock and Neuberger Berman don't write checks for a company they think is going to sit in PE hands for another five years. They came in because they figured there'd be a liquidity event in the next 18 to 36 months. IPO or secondary sale.

The third one is worth thinking about.

Rubix chairman Sleebus said a few words in the announcement to explain why Morkeberg got the nod. Direct quote: "He has managed the cost base and protected profitability with discipline and rigor, establishing resilience as a hallmark of our business."

When was the last time you saw a company about to enter a high-growth phase hand the CEO role to a career HR person, and describe him in these words? These words describe one job: hold costs down, hold profits steady, make the numbers look as good as possible when it's time to sell.

Back to compressed air.

Between 2021 and 2025, Rubix picked up compressed air businesses in Poland, the UK, Spain, and France. In November 2025 it also bought Konrad Haluk in Germany. Haluk does bearings, not pure compressed air, but it's based in Baden-Württemberg, Kaeser and Boge's backyard.

I thought about laying these deals out in chronological order, then decided that would make you think this was some meticulously planned strategic blueprint. It probably wasn't. PE-backed companies doing acquisitions, a lot of the time it just goes: a seller comes to the table, they talk, if the price works they buy. CompCare's founders Griffiths and Knowles probably just wanted to retire. HEC in Barcelona only came together in 2019 from a merger of two smaller outfits and probably never planned to stay independent for long. HR Hafner was a family business; the founder was probably hitting succession age. Airflux's PE shareholders at Nord Capital had been in for seven, eight years. Time to get out.

The result is the same. Whatever each deal's individual story was, after this run, Rubix had a compressed air service network across four major European markets. CompCare does system optimization and VSD retrofits. Airflux does nationwide maintenance and equipment sales. HEC does regional service. Stack those on top of Rubix's existing 780-plus industrial distribution locations and you've got a channel that no single OEM's dealer network is likely to replicate on its own.

What this means for OEMs is something I don't think most compressor manufacturers have really thought through yet.

Atlas Copco did 29 acquisitions in 2025. A good number were distributors. Air Compressor Works in Florida, 50 people, $18 million revenue, folded straight into Quincy's service division. Centroar in Brazil, 28 people, compressor distribution for mining and construction. Zind Verfahrenstechnik in Germany, a filter element distributor with no manufacturing, no R&D, no patents. Ingersoll Rand spent $168 million in Italy. Parker Hannifin spent $9.25 billion on Filtration Group.

OEMs are buying distributors. PE platforms are buying distributors. The two are doing it for completely different reasons.

For end users, the impact is subtle. And real.

For forty years, Airflux's value proposition was independence. Customers trusted Airflux's recommendations because Airflux didn't owe any OEM anything. Your operating conditions suit an Atlas Copco GA VSD+, they recommend the GA VSD+. A Kaeser SFC saves you more money, they recommend the SFC. That kind of neutral technical advice is extremely rare in industrial procurement, because most distributors are locked to a brand. Airflux wasn't. That's the fundamental reason it kept winning customers for forty years.

Rubix, in theory, isn't locked to a brand either. But Rubix is also a platform doing over $3.15 billion in annual procurement. When you're buying more than $3.15 billion a year, your relationship with suppliers stops being "I recommend the best product" and becomes "I recommend the product from whoever gives me the best purchasing terms." Not because the people at Rubix are bad. Because the company's KPIs and incentive structures point behavior in that direction. A company sitting on $1.26 billion in debt needs to wring as much profit as it can out of every business line. The tension between independent technical advice and profit maximization is not something you resolve by saying "we serve the customer."

36% to 72%. Double the efficiency. That gap is the entire reason Rubix's compressed air business exists. A French factory might spend $210,000 a year on electricity for compressed air. If you can cut that in half, you charge $30,000 to $50,000 a year in service fees. The customer thinks they won. You also won. The contract runs three to five years.

Rubix bought the finish line in one deal.

I don't know what Boutry is doing in Lille right now. Maybe he's enjoying retirement, living off the returns from two exits, the Nord Capital round and the Rubix round, catching sun on the northern French coast. Maybe he doesn't care who owns the Airflux equity, so long as the service network he built is still running. Maybe he saw his name missing from the Rubix press release and shrugged.

One thing is for sure. Those 80 Airflux technicians, the people with wrenches and tool bags, adjusting pressure dewpoint temperatures in factory compressor rooms across France, are doing exactly the same work they did last year. Their skills haven't changed. Their customer relationships haven't changed. The rotary screw machines they fix every day aren't going to spin two more turns or two fewer because the shareholder went from Nord Capital to Advent International. They are the only part of this entire value chain that creates real value.

The equity structure above them has turned over three times. 2014, Nord Capital came in, first turn. 2025, Rubix/Advent picked it up, second turn. Whenever Advent exits in the future, IPO or sale to the next owner, third turn. Every turn, a group of people made money in the process. Not one of them knows how to take the discharge pressure on a GA 90 VSD+ from 8.5 bar down to 7.5 bar to save a customer $12,600 a year in electricity.

When Morkeberg took over, he said something. He said Rubix's mission is "to keep the wheels of industry turning," and that his colleagues work hard at it every day.