About MPI Diffusers

The FlexCap™ Coarse Bubble Diffuser business, previously owned by Mooers Products, Inc in Glendale Wisconsin, was purchased by Bernard J Beemster on Dec 31, 2024 and has been rebranded as MPI Diffusers. The business is now headquartered in East Troy, Wisconsin.

Beemster has owned or operated several other business in the environmental field, including management of the Wastewater Treatment Division at Autotrol Corporation (a manufacturer of process equipment), founding Beemster and Associates (a consulting firm), heading business development at Biotronics Corporation (an R&D company) and as cofounder and President of ASA/ChemScan (a manufacturer of process analyzers and control systems for advanced water and wastewater treatment). Beemster also owns and operates Bernardo’s Foods, a manufacturer of preserved specialty food products.

The diffusers were originally designed at Autotrol Corporation in the late 1970’s for the business unit headed by Beemster. The rights were acquired by Doug Moores in 1985 who founded Mooers Products, Inc and operated the business until his death in 2011. The business was then operated by Barbra Mooers from 2011 to 2023. Beemster, who was also one of the original inventors of the diffuser, was an advisor to the Mooers Products business throughout its history and helped operate the business from mid-2023 to the end of 2024, when he purchased the business from the Mooers family.

Many thousands of coarse bubble diffusers were manufactured over the 40-year history of the business and were sold to customers in the water and wastewater treatment industries. Major applications include sludge mixing, aerobic digester aeration, secondary wastewater
treatment, BNR re-aeration, RBC and fixed film aeration, air stripping and many others.

The FlexCap ™ Diffuser is considered perfect for applications where oxygen transfer must be accomplished in a liquid that also contains very high solids. The 3 to 5 mm average bubble size offers an ideal compromise between oxygen transfer efficiency and mixing of the solids. This bubble size is slightly larger than a “fine bubble” diffuser but is much smaller than many other types of “coarse bubble” diffusers.

The unique design of the™ diffuser expels bubbles at the underside periphery between a solid EDPM cap and a solid polypropytene base. There are n holes in either the cap or the base, which allows the cap to be held tighter under high air pressure, act as an effective check valve when air flow is ended and scour the periphery during service. A service life of more than 15 years has been noted in some applications.