Filtrex History

The patents and processes behind Filtrex, Inc. were pioneered some 60 years ago by PER Corporation's president, Russ Hobson. He was a giant in liquid and solid separation at the time and developed the regenerative Flex-Tube element, originally focused on the dry-cleaning industry (filtering carbon tetrachloride and perchlorethylene). Following the success and wide acceptance of the regenerative concept, it was recognized that it could be extended into other applications and industries.

One of the potential innovations in the aqueous-filtration field was the development of a small-footprint, highly efficient filtration system. At the time, the predominant technology was relatively slow sand filtration, which required large amounts of square footage per application rate.

Following the initial research and development efforts, our first listing was applied for and approved under the old NSF Standard Number 9 in 1964. The regenerative process was fully embraced in the current "Extended Cycle" series of filters. PER Corporation had a broad range of success in both the dry-cleaning and aquatics markets. An industrial filtration line for commercial applications was subsequently introduced.

At this time, Vincent A. Pisani (our founder) was brought in from the Detrex Corporation of Oklahoma City, OK. He added structure, design engineering, and marketing focus to PER Corp's efforts. In 1969, Russ Hobson lost his partner and chief financial officer, leading him to liquidate the company in 1970. The aquatics division, including both commercial and residential segments, was sold to Hayward Corporation. Vince handled the transfer and took a position as general manager of the aquatics division of Hayward. While there, he was instrumental in developing the very popular residential EC series of filters. After several years, Hayward decided to spin off the commercial segment of the product line. The assets, design, and copyrights were transferred to Vince Pisani, and Filtrex, Incorporated, was established in 1974.

The company was run out of his home for ten years, with his wife Anne serving as secretary and treasurer. Alongside several other engineers on staff, Vince developed Filtrex's Integrated Filter Controller to maintain cleaning schedules and media regeneration on larger models and later extended its application to smaller filters with the MOD I Automated Filter Controller. In 1984, "Stretch" models were added to increase the system capacities of our smaller filters without compromising floor space.

Kenneth A. Bergstrom was brought on as senior engineering supervisor in 1988. With 15 years of experience in electronics systems, he was responsible for completely digitizing the filter controller without moving parts. The MOD I "Solid-State Controller" furthered convenience by making troubleshooting easy and reducing energy usage and replacement costs. When Vince passed away in 1997, the company was purchased from the Pisani family by the Bergstrom Group, consisting of Ken and several other employees.

Ken served as president of Filtrex, Inc. for almost 25 years, applying his expertise in engineering and fluid dynamics to continue improving the filters' efficiency. In addition to the MOD I SSC retrofits over the years, he implemented the use of Variable Frequency Drives to control the speed of pumps and fans rather than by throttling valves, and he integrated them with the filter controller when needed. Beyond technical advancements, he participated in the National Sanitation Foundation's joint committees in creating new standards. His salesmanship helped establish our presence in the international market, and his commitment to customer satisfaction built a reputational example for us to follow in his absence.