7.8　Assembly of Flue Gas Inlets ＆ Outlets

7.8.1　The permissible deviation of the angle of the inlet flue gas duct is 0.2°.

7.8.2　The permissible deviation of the distance between stiffeners for inlet & outlet flue gas duct shall not exceed 6mm.

7.8.3　The permissible deviation of elevations for flue gas inlets and outlets is 5mm.

7.8.4　Circular flue gas ducts shall be assembled as specified below：

1　The permissible deviation of external perimeter is 0.3% and not greater than 15mm.

2　The off-set of butt weld is not greater than 1.0mm.

3　The hammering depth of the internal surface is not greater than 1.0mm.The maximum local unevenness is not greater than 4mm.The permissible deviation of the diameter is not greater than 0.1% of the diameter.

7.8.5　Rectangular flue gas ducts shall be assembled as specified below：

1.The permissible deviation of the length and width of flue duct outer end face shall not be greater than 3mm.

2.The off-set of butt welds shall not be greater than 1.5mm.

3.The hammering depth of the internal surface is not greater than 1.5mm.The maximum local unevenness is not greater than 6mm.

7.8.6　The deviation of the distance between flue gas duct inlet & outlet flanges and the absorber centerline shall not be greater than 10mm.

7.8.7　The sealing surfaces of flue gas duct inlet & outlet flanges shall be free of any obvious warping deformations and welding beadings.All butt welds shall be ground smooth.The permissible straightness deviation for flange edges shall be 3mm.

7.8.8　All assemblies of flue gas duct inlets and outlets shall be rigid enough，and shall be temporarily reinforced during assembling where necessary.