Parker Hannifin Corp. has purchased the Farr Engine Air Filter operation from Camfil Farr. Farr produces air filtration products for diesel-powered heavy-duty and severe-service vehicles, including fire trucks, buses, off-highway equipment and mining machinery. Purchased by Camfil in 2000, Farr recorded sales revenues of $15 million last year. It will become part of Parker’s Filtration Group, which