DwyerOmega Takes SOR’s Measure

DwyerOmega, a portfolio company of Arcline Investment Management, has acquired SOR Controls Group, a manufacturer of instruments used to monitor pressure, temperature, liquid levels and flow inside industrial plants.

SOR was founded in 1946 and has been owned by the founding Dunlap family ever since. It is the tenth acquisition DwyerOmega has made since Arcline bought Dwyer Instruments in 2021 and its third add-on this year.

SOR designs and manufactures switches, transmitters and sensors used to monitor process conditions in refineries, chemical plants, power stations and water treatment facilities. Its pressure switches trigger an alarm or shut down equipment when pressure in a line crosses a set point, while its transmitters send continuous readings to a plant’s control system. Level switches and magnetic level indicators track liquids in tanks and vessels, and flow switches confirm that fluid is moving through a pipe.

The company operates under three brands. SOR Measurement Controls makes switches and transmitters, including nuclear-qualified pressure switches it has supplied to power plants since 1982. SSi Temperature Sensors makes thermocouples and resistance temperature detectors, which convert heat into an electrical signal, along with thermowells, the protective metal sleeves that hold the sensors inside a process line. SENSOR Sampling Systems makes closed-loop equipment that allows operators to take a sample of a hydrocarbon or chemical without releasing it into the air. Customers include chemical producers, oil and gas companies, power generators, water utilities and equipment manufacturers.

Roy Dunlap founded the company in 1946 as a machine shop called MechniArts, using $2,000 he received from the Navy for his service during World War II. In 1956, he and a University of Kansas physics professor developed a pressure switch sealed with a static O-ring. That product eventually gave the company its name: Static O Ring in 1965 and SOR in 1978. Under the Dunlap family, SOR acquired Smart Sensors, a Houston-based maker of temperature sensors, in 2013 and SETEX Products, a Beaumont, Texas-based maker of thermowells, in 2014. It formed SENSOR Sampling Systems in Houston in 2016.Today, SOR operates a 110,000-square-foot plant and machine shop in Lenexa, Kansas, along with manufacturing in Houston and sales offices in Beijing, Dubai and Chennai, India. The company is led by Chairman Alaya Belmonte and is headquartered about 15 miles southwest of Kansas City.

“There has never been a more exciting time for SOR,” said Ms. Belmonte. “We have a proud history built on putting people first, delivering quality, and doing what’s right for our customers. Becoming part of DwyerOmega is a new chapter that strengthens our ability to build on that legacy and expand our offerings in meaningful ways.”

“We are excited to welcome SOR Controls Group’s product portfolio to the DwyerOmega family,” said Chuck Dubois, the CEO of DwyerOmega. “SOR brings eight decades of expertise in safety-critical process instrumentation and advances our vision of being the provider of choice for measurement technologies to customers globally.”

DwyerOmega, based in Michigan City, Indiana, about 60 miles east of Chicago, makes instruments used to measure and control pressure, temperature, humidity, air quality, gas and flow for industrial, building and laboratory customers. The company has more than 3,000 employees at 50 locations in 18 countries, including 26 manufacturing and engineering sites, and sells under 21 brands. Its roots are Dwyer Instruments, founded in 1931 and known for the Magnehelic differential-pressure gauge, and Omega Engineering, founded in 1962 in Stamford, Connecticut.

Arcline acquired Dwyer Instruments from its family owners in July 2021. The platform then added Universal Flow Monitors, a Michigan-based maker of flow meters (2021); Omega Engineering, a Connecticut-based maker of temperature and process sensing products acquired from Spectris for $525 million, or 20.4x Omega’s 2021 adjusted EBITDA (2022); Automation Components, a Wisconsin-based maker of building-automation sensors (2023); and Miljoco, a Michigan-based maker of temperature and pressure gauges acquired from Foundation Investment Partners (2024).

Later additions were Process Sensing Technologies, an England-based sensor maker acquired from AEA Investors and Battery Ventures (2024); Macurco, a South Dakota-based maker of gas detectors (2025); Consistec, a Brazil-based maker of ruggedized temperature sensors (2025); Burns Engineering, a Minnesota-based maker of precision temperature sensors (2026); and Lake Shore Cryotronics, an Ohio-based maker of instruments that measure temperatures near absolute zero (2026).

SOR adds pressure switches and level instruments used in safety-critical and nuclear applications to a DwyerOmega lineup built largely around temperature, humidity and gas measurement.

The U.S. process instrumentation market was worth $5.6 billion in 2025 and is projected to reach $7.4 billion by 2034, a 3.0% annual growth rate, according to Renub Research. Mordor Intelligence sizes the global market at $19.7 billion in 2026, with North America accounting for about 45% of revenue, and points to the replacement of instruments in aging North American plants as a source of growth.

The global market for pressure switches alone is projected to grow from $2.8 billion in 2025 to $3.5 billion by 2030, according to MarketsandMarkets.

SOR competes with Rosemount, a Shakopee, Minnesota-based maker of pressure and level instruments founded in 1956 and owned by Emerson since 1976; Endress+Hauser, a family-controlled Swiss instrument maker founded in 1953; WIKA, a German pressure and temperature instrument maker founded in 1946 and controlled by the Wiegand family; Magnetrol, an Aurora, Illinois-based level instrument maker founded in 1932 and owned by AMETEK since 2021; and United Electric Controls, a privately held Watertown, Massachusetts-based maker of pressure and temperature switches founded in 1931.

Recent private equity activity in industrial sensing includes the October 2025 acquisition of Carson, California-based thermocouple maker Duro-Sense by Industrial Control Solutions, a platform of LDR Partners, and Renovo Capital’s October 2025 sale of Coppell, Texas-based liquid-level sensor maker Rochester Sensors to Amphenol.

Arcline invests in what it calls industrial compounders, companies with high switching costs, regulatory barriers and long product lives. Sectors of interest include aerospace and defense, engineered components, critical infrastructure, and test and measurement.

Arcline is currently investing from its fourth fund, Arcline Capital Partners IV LP, which closed in October 2025 with $6.0 billion of capital, up from $4.5 billion for its third fund in 2023.

Earlier transactions by Arcline this year include the take-private of AstroNova in August 2026 and the acquisition of Continental Aerospace Technologies from AVIC for about $535 million in June 2026. The firm was founded in 2018 by Chief Executive Officer Rajeev Amara and is headquartered in Nashville, Tennessee.

EC M&A was the financial advisor to Arcline.