7.3　Slag Hole Devices and Taphole Sleeves

7.3.1　For the large sleeve，secondary sleeve，third sleeve and small sleeve of slag hole，the pressure test shall be taken before installation and the requirements of the design document shall be met.The requirements of Appendix D of this standard shall be met when there is no requirement in the design document.After installation，the water test shall be taken at the working pressure.The inlet and outlet water shall be smooth.The joint shall be free of leakage.

7.3.2　After the fixed devices of the large sleeve，the secondary sleeve，the third sleeve and the small sleeve of slag hole are supported tightly，the gap between the top plate and the slag hole flange shall meet the requirements of the design document.When there is no requirement in the design document，the gap should not be less than 10mm.The tightly-closing face among the large sleeve，the secondary sleeve，the third sleeve and the small sleeve shall be checked by the 0.10mm feeler gauge，and the filling depth shall not be larger than 1/3 of the contact length.

7.3.3　The welding of the flange of the slag hole and taphole sleeve shall be firm and reliable and be free of lack of welding.In addition，the weld metal shall be full.

7.3.4　The allowable deviation of installation of the flange of slag hole device and taphole sleeve shall meet the following requirements:

1　The center position of the flange face shall be measured along the circle of the blast furnace shell from the specified start point，with the allowable deviation of 4'.

2　The elevation of the flange shall be checked by level gauge or steel ruler，with the allowable deviation of±5.0mm.

3　The levelness of the horizontal center line of the flange face within the horizontal diameter shall be checked by level gauge or steel ruler，with the allowable deviation of 3.0mm.