U.S. Air Force Airman 1st Class William Davey, 633rd Civil Engineer Squadron heating, ventilation and air conditioning apprentice, saws through a chill water line March 19, 2012, at Langley Air Force Base, Va. The outer water lines are also replaced, expanding the service life of the new chiller. (U.S. Air Force photo by Senior Airman Stephanie Rubi/Released)