Conoco, Inc., Citgo Petroleum Corporation and Lake Charlesharbor and Terminal District, Plaintiffs-appellants, v. the United States Foreign-trade Zones Board; Barbara H.franklin, Secretary of Commerce, As Chairman and Executiveofficer of the Foreign-trade Zones Board; Nicholas F.brady, Secretary of the Department of the Treasury, Asmember of the Foreign-trade Zones Board; Michael P.w.stone, Secretary of the Army, As a Member of Theforeign-trade Zones Board and John J. Da Ponte, Jr.,executive Secretary of the Foreign-trade Zones Board,defendants-appellees