The inspection range before installation of boilers

including steam drum

header

main pipelines of feed-water

piping system of the heating surface

and load-bearing structures etc.

has been presented.The focal points of inspection for steam drums and headers have to concentrated to angle welding seams on tubes' sockets;for the piping system of heating surfaces

attention has to be paid to non-circularity and wall-thickness of the tube bends;the defects existing on main pipelines of feed-water can be discovered through macroscopic inspection

and the problem of exceeding set standard for wall-thickness can be discovered through wall-thickness measurement;for load-bearing structures

attention has to be paid to prevention of blowhole defects occurred during the time of welding.The sequence and focal points etc.of inspection have been summarized up.