Profile: L&L Mechanical Construction and Design Co. Inc. specializes in plant start-ups, cooling towers and chiller piping. Our process pipefitting includes utility piping , sprinkler systems and sewage systems using steel, stainless steel, nickel, copper, plastic, pvc, fiberglass, copper, glass & glass-lined pipe. We concentrate on electric arc, heliarc welding and brazing using carbon steel, stainless steel, monel & aluminum.