Installation of a new Debutanizer Unit at the Conoco Refinery in Commerce City.  Scope of work included the installation of owner furnished instruments, the supply and installation of cable tray; rigid conduit, power, control and instrumentation wiring.  Steel structure was four stories high with an adjacent 140′ stack.  A second area W27, was located in an existing and operating area oof the plant.  Work environment was Class 1, Division 1, and Class 1, Division 2.