ErtelAlsop is the result of the merger of Ertel Engineering and Alsop Engineering. Ertel Engineering was founded by Frederick Ertel in 1932 in New York City. He originally manufactured and sold depth filter media for the pharmaceutical industry. ErtelAlsop is an innovator in the manufacturing of depth filter media and machinery for liquid filtration since the 1920’s. As such, ErtelAlsop is your one source for all depth filtration and liquid processing products.

Company details

132 Flatbush Avenue , Kingston , NY 12401 USA
View in map

Find locations served, office locations, manufacturers and our distributors.

Business Type:
Industry Type:
Water Filtration and Separation
Market Focus:
Nationally (across the country)
Year Founded:


ErtelAlsop: A History of Innovation, a Future of Invention

ErtelAlsop is the result of the merger of Ertel Engineering and Alsop Engineering. Ertel Engineering was founded by Frederick Ertel in 1932 in New York City. He originally manufactured and sold depth filter media for the pharmaceutical industry. In 1938, he moved his company to Kingston, New York, about 100 miles north of Manhattan, on the Hudson River. In Kingston, Ertel expanded the business to include plate and frame filter presses, pumps, agitators, bottle fillers, and other equipment for liquid processing. In 1943, Ertel developed the first pyrogen retentive media for Bristol Labs to use in the manufacturing of penicillin for World War II. 1979 was the year that Ertel patented the first enclosed horizontal plate and frame filter press. The design was created in conjunction with Avon to eliminate vapors from Avon's production floor in order to improve working conditions. As usual, Ertel was willing to go the extra mile to provide a solution for its customer's application.

Alsop Engineering was founded by Samuel Alsop in 1920. The Sealed Disc Filter, Alsop's first product, was an enclosed horizontal plate filter. As a matter of fact, Alsop's first filter sheets were manufactured for them by Ertel Engineering. In the 1940's, Alsop invented an accordion shaped filter cartridge, which provided an enclosed filtration environment and much shorter changeover cycles than plate and frame filter presses. This was the first Zeta-Pak lenticular cartridge. In addition to the cartridges, Alsop designed the corresponding filter housings. Originally vertical with removable covers, these housings have evolved to include horizontal mounting, ASME code, and sanitary designs. Alsop's product line was not limited to filters alone, it also included tanks and portable mixers. Available in both direct and gear-driven models, the mixers were unique because the same base components were used from 1/4 to 3 horsepower designs. This feature allowed the end user to maintain common parts for various sized agitators.

Today, ErtelAlsop maintains the innovative nature of its founders. The BioClean™ sanitary plate design, the 1S PharmaScale™ Filter, the Bio-Pak Double O-Ring Lenticular Cartridge, and Validation Guides for filtration media and equipment are our latest additions to the legacy begun by Fred Ertel and Sam Alsop.

ErtelAlsop's customer base is filled with clients who have been buying from us for over 80 years. Our commitment to customer service and willingness to modify our designs to meet customer requirements continues to make ErtelAlsop stand apart from our competitors.

Environmental Remediation

The job of protecting our Earth's environment is of critical importance. The growth of the world's population, combined with the rapid expansion in the industrial and agricultural sectors, has caused some inevitable contamination of air, water and soil. Viable treatment strategies and technologies are needed in order to prevent adverse impacts on human health and the environment.

ErtelAlsop's EA Series of Recessed Chamber Filter Presses is specially designed to handle applications such as Lagoon Sludge, Hazardous Waste Dewatering, Leachate Treatment and Soil Washing. This line provides one of the most efficient means of liquid/solid separation through pressure filtration, either for solution filtration or sludge volume reduction. With plate sizes from 470 mm through 1500 mm, these presses offer a simple, reliable method of compressing and dewatering solids into cakes of 25-60% total concentration. This in turn provides clearer filtrate solutions than systems, which remove only free water.

Industrial Wastewater Market

As industrial wastewater requirements become more stringent, effective filtration increases in importance. Assistance in achieving this comes in the form of the EA Series line of Recessed Chamber Filter Presses. Slurries of wastewater, such as metal hydroxides, alum sludges, etc., are pumped into the chambers of the filter press. Filtrate passes through the filter cloth and solids are retained. Solids collect on the cloth, forming an excellent filter cake, as if one were to intentionally pre-coat the cloth. As additional solids are pumped into the chamber, the cake continues to build until the entire chamber is full of dewatered solids. The press is then cleaned and recycled.

The EA Series is ideally suited to perform these tasks. Available with Recessed Chamber or Diaphragm Plates and able to accommodate a wide variety of cloths, this line offers cake volumes from 0.5-300 cubic feet. Options such as plate shifters, automatic hydraulic closures and mobile cake carts are also available.