PLL

Pall Corporation

A maker of filtration, separation, and purification systems, Pall Corporation builds the filters that keep airplane engines, hydraulic systems, semiconductors, and even beer clean and contaminant-free. It was founded in 1946 by chemist Dr. David B. Pall, who got his start designing filters for the Manhattan Project's uranium-isotope separation work, and the company was renamed after him in 1957. The business began as a one-person shop behind a Brooklyn shoe-shine parlor before growing into one of the world's largest filtration companies.