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Durco Filters™ by Ascension Industries

From Enzinger, Duriron, Durco, FSD, and AquaCare to Durco Filters by Ascension - 1878 to Present

Enzinger Filter Company

Germany was the center of brewing technology in the 19th century. Leaf filters were an outgrowth of the brewing industry's need for filtering beer and producing a long shelf-life product for distribution. In 1878, Lorenz A. Enzinger of Worms, Germany brought the firm L. A. Enzinger into being that, just like the Seitz-Werke founded by Theobald Friedrich Seitz and Georg Heinrich Seitz, initially focused on the production of filter products. On June 4,1878 Mr. Enzinger filed for a patent on a device with paper filter layers for filtering of hazy and foaming liquids at the German Imperial Patent Office. The patent specification received the number 5159 and was confirmed on May 29,1879.  That same year he formed the company, Enzinger Filter Company, to produce this new filtration equipment for the brewing industry in Germany.

The first beer filter was presented at a brewing exhibition in Munich in 1880 by Enzinger. The filter was designed in a horizontal configuration, with individual plates having inlet and outlet channels, similar to modern plate and frame filters. Back then, the plate material was black iron with valves and meters made from copper and brass. Filter media was made of paper leaves which had to be changed after each filtration cycle.

The next generation of beer filters was developed early in the 1900's, again by the Enzinger company. This filter was a vertical design using brass bowls to house pulp cakes. Pulp cake was prepared from cotton fibers mixed with asbestos. The main advantage of pulp filtration was the possibility to re-use the material for 3 to 5 filtration batches, reducing labor, cost, and downtime. Once spent, the pulp cake was removed from the brass bowls, rinsed and reprocessed in a pulp press to make new cakes. Pulp filtration was the first "recycling technology" used in breweries, however it required a high level of water consumption and hours of labor. Following the use of the pulp filter with its labor and water use problems, the first design for Diatomaceous Earth (DE) filters by Enzinger was based on a plate and frame filter using support sheets. Following that Enzinger design, Schenk Filterbau introduced a variation of the horizontal pressure plate DE design, and Enzinger then developed and introduced the candle type DE filter. These three filters, while improved from the early models, remained the most common platforms for primary filtration in breweries for decades. Today's filtering and polishing in the brewing industry is still dominated by the basic Enzinger design, slightly modified over the years, as built today by Durco Filters.

The Duriron Company

Duriron was founded in 1912 by a Dayton foundryman, Pierce D. Schenk, and two associates, J. Richman Pitman, a DuPont explosives production engineer and William F. Hall, a New York Financier. The company derives its name from a high silicon cast iron alloy, Duriron (durable iron), which rapidly became an industry standard for handling extremely corrosive materials. Duriron "denitrating towers" were in high demand during World War I (1914-1918) for safe handling of hot mixtures of Nitric and Sulfuric acids during the manufacturing of explosives. As a result of the war, the company expanded tenfold, increasing its work force from 150 to 1500.

During the 1920s and 30s, Duriron faced a major readjustment period since "denitrating towers" used in the war effort were no longer in demand. The readjustment included the development of a line of more "off the shelf" Duriron pumps and valves for use in the broad chemical process industries. The breadth of alloys in which pumps and valves were offered was also greatly expanded to include a variety of nickel based alloys, one of which, Durimet-20 (a joint development and patent of Ohio State and Duriron), was to become a world standard for handling certain difficult chemicals.

Duriron Purchases Enzinger and Moves to Western New York

Durco Filtration Division is Founded

In 1933, Duriron purchased the Enzinger Filter Company in Germany and brought that company to Angola, New York and founded the Durco Filtration Division specializing in beer and chemical filtration systems. The redirection and product expansion of both pumps and filters would begin to reap great returns in the 1940s as Duriron's pumps and filters became more widely accepted. During World War II, two thirds of Duriron's production was devoted to providing pumps, filters, and valves for production of Plutonium and Uranium for the Manhattan Project which developed the atomic bomb. The company won the prestigious Army/Navy "E" award for these efforts. Duriron became a publicly traded company in 1946 on the New York Stock Exchange.

After World War II, Duriron and Durco Filters grew consistently in the 1950s, 60s, and 70s through new product innovation and technical sales force expansion to serve the fast growing chemical process industries throughout the U.S., Canada and, in later years, in Europe as well. New pump products included the first use of Teflon® as a sealing substance in a patented special alloy non-lubricated plug valve that quickly acquired a dominant position in the chemical valve business, and the successful expansion of the filtration products into filter presses, tubular filters, and Nutsche filters in major chemical companies around the world. As a result, revenues grew to $125 million in 1979.

In spite of a decline in revenues in the first years of the 1980s, the company grew to $605 million in 1996, largely through a number of strategic acquisitions that expanded the line of complimentary products available for sale to the chemical process industries. These traditional filtration systems and the enhancements made to the other existing filtration products were to become the "standard filter products" for much of the American expansion in the industrial market up through the 1990's. By 1997 the company employed a total of 6,000 people in locations throughout the world and was a worldwide leader in engineered valves, filters, pumps, control valves, and mechanical seals for the mining, chemical process, and refining industries.

At that time, the 85 year old Duriron Corporation lost its name and identity as a company in July 1997 as the company was acquired and split into 2 parts:

Aquacare and FSD

At the split, the filtration group was sold in 1997 to Aquacare and renamed Durco Filtration and Separations Division (FSD) headquartered in Angola, New York. The filtration division continued to grow until it was purchased by Ascension Industries, Inc. in 2003.

Durco Filters by Ascension Industries

In 2003, Ascension Industries acquired the rights to the Durco Filters line of industrial filtration products and formed the Durco Filters division of Ascension Industries. As part of this acquisition, all engineering and manufacturing was moved from Angola to North Tonawanda, New York.

Today, with more than 130 years of filtration experience on a worldwide basis, the Durco Filters products are still one of the world leaders in product innovation and technology, continuing to grow and serve an ever expanding variety of industries including chemical, mining, food & beverage, metal processing, oil refining, and petrochemicals. The product technologies invented during the 19th & 20th centuries are still viable in the industrial environment even in the 21st century. Fortunately, modern controls and the latest technology in materials and workmanship have enhanced the designs and construction of the filtration systems, but the heart of the design and product known as Durco Filters is as reliable as it has always been for our customer's most difficult applications.

The 5 main product lines, and all their derivative products and sizes, form the core of the Durco Filters offerings manufactured in America with all American labor, materials, and craftsmanship. This unbeatable combination of quality and product longevity has given Durco Filters its global reputation as the trusted filtration solution proven to work in the most demanding environments.

For all our worldwide customers, Durco Filters products are the Proven, Trusted Solutions™ to their filtration needs.

Pressure Leaf Filters
Sludge Dryers
Tubular Backwash Filters
Pressure Nutsche
Filter Presses