7.7　Furnace Top Guard Shield

7.7.1　The fixing method for the furnace top guard shield shall meet the requirements of the design document.

7.7.2　The allowable deviation of installation of the furnace top guard shield shell shall meet the following requirements:

1　The diameter of the inner circle of the upper edge of the guard shield shall be checked by steel ruler，with the allowable deviation of±20mm.

2　The height difference between the adjacent guard shield shall be checked by level gaugeor steel ruler，with the allowable deviation of 6mm.

3　The gap between the guard shields shall be checked by steel ruler.Both the allowable deviation of the gap of the horizontal seam and that of the perpendicular seam is±15mm.

4　The distance from the position of a stock rod hole on the arch amour to the center line of the furnace body shall be checked by steel ruler，with the allowable deviation of±10.0mm.The angle of the horizontal position shall be checked by steel ruler and converted，with the allowable deviation of±15'.