SJE Inc. acquired by Audax Private Equity

SJE, a leading manufacturer of control solutions for the water and wastewater industry, has sold a majority equity interest to Audax Private Equity (“Audax”). The investment from Audax comes as SJE aims for continued growth and expansion within the controls industry.

Founder, Steve Johnston, started S. J. Electro Systems in 1975 after creating the original version of the Tank Alert alarm in his garage. In 1987, Steve decided he wanted to pass the company on to his employees by establishing an Employee Stock Ownership Plan (“ESOP”), allowing employees to share in the successes that they were helping to create.

“For a highly successful employee-owned company, the timing was right for us to transition ownership to ensure the best return for our employees,” said Dave Thomas, President and CEO of SJE. “We had a tremendous opportunity to make the retirement benefit of the ESOP an immediate reality for our team. Following the investment from Audax, we will continue to operate as we have historically, and remain committed to our core values of unity, humility, agility, drive, and ownership.”

Over the past 45 years, SJE has grown significantly, bringing a number of innovative products to the market. SJE currently has seven locations worldwide and nearly 500 employees. In 2020, a year of a global pandemic, SJE had a record year in both sales and profitability.

“SJE is an amazing success story. From our humble beginnings, we have emerged as a leader in our industry,” continued Thomas.

“Study our history, and you’ll see our success derives from a culture that has always driven growth. Now we have the financial resources to make the capital improvements and acquisitions necessary to expand on our position in the industry,” concluded Thomas.

SJE will look to benefit from the strategic and financial resources Audax brings to their portfolio companies. These resources will help drive investments in the business, support growth strategy, and enable SJE to continue pursuing acquisitions.

“Audax supports strong leadership teams to build companies. We focus on buying and then building market-leading companies that are poised for growth,” said Ryan Bruehlmann, Managing Director of Audax Private Equity. “We see tremendous value in SJE’s culture of teamwork, commitment to purpose and values, and strong desire to succeed.”

Learn more about SJE at

About SJE Inc.

SJE was founded in 1975 by Steve Johnston. Today, over 45 years later, SJE has grown into a leading controls technology company throughout the United States and Canada, as well as into global markets. SJE is comprised of well-respected brands — CSI Controls, PRIMEX, SJE Rhombus — all known for their innovation and quality. With locations throughout the United States and Asia, SJE offers a wide variety of control products for residential, commercial, municipal and industrial markets. From control panels utilizing embedded circuit board technology, to complete control and monitoring systems designed and built to individual specifications, SJE represents the most reliable integration of engineering and manufacturing capabilities in the industry.

About Audax Private Equity

Audax Group is a leading alternative investment manager with offices in Boston, New York, and San Francisco. Since its founding in 1999, the firm has raised over $27 billion in capital across its Private Equity and Private Debt businesses. Audax Private Equity has invested over $6 billion in more than 135 platforms and over 950 add-on companies, and is currently investing out of its $3.5 billion, sixth private equity fund. Through its disciplined Buy & Build approach, Audax seeks to help platform companies execute add-on acquisitions that fuel revenue growth, optimize operations, and significantly increase equity value. With more than 250 employees and over 100 investment professionals, the firm is a leading capital partner for North American middle market companies. For more information, visit the Audax Private Equity website: or follow us on LinkedIn.