PNR

Pentair Plc

A maker of water treatment, filtration, and pool equipment, Pentair's brands like Fleck and Autotrol control valves keep water softeners and filters running in homes and businesses worldwide. Five former Litton Industries employees founded it in 1966 in Minnesota, naming it for the Greek root "penta" (five) plus "air" — because their original plan was high-altitude research balloons. It later passed through plastic canoes, software, and power tools before becoming a water-focused company, and it spun off its electrical business as nVent in 2018.