CLAIRTON, a city of Allegheny county, Pennsylvania, U.S.A., on the Monongahela river, tom. S.E. of Pittsburgh ; served by the Pennsylvania, the Pittsburgh and West Virginia and the Union railways. It was formed in 1922 by the consolidation of the boroughs of Clairton, North Clairton and Wilson, which in 1920 had a combined population of 10,777. The city's popu lation in 1930 was 15,291 by the Federal census, and the assessed valuation of property was about $26,000,000. Clairton has im portant manufactures of structural iron, steel, boiler tubes, river boats and barges and an immense by-product coke plant (22 bat teries, 1,484 ovens) which uses 8,000,000 tons of coal in a year.