8.5　Charging Bucket

8.5.1　The grouping of the charging bucket shall meet the following requirements:

1　When blocking into upper，middle and lower sections or upper and lower sections for supply，the charging bucket shall be grouped on the installation site.The grouping of the upper，middle and lower sections or upper and lower sections may be conducted by setting up the bracket on the platform or the solid ground.

2　The upper，middle and lower sections or upper and lower sections shall be grouped in sequence.The overall dimension of the charging bucket shall be adjusted and detected.The parallelism of the upper and lower flanges and the concentricity of the upper and lower mouths shall meet the requirements of the design document and shall meet the following requirements when there is no requirement in the design document:

1）The parallelism of the upper and lower flanges shall be checked by level gaugeor steel ruler，with the allowable deviation of 3mm.

2）The concentricity of the upper and lower mouths shall be checked by steel ruler through hanging the pendant，with the allowable deviation of 5mm.

8.5.2　The welding of the charging bucket shall meet the following requirements:

1　Before welding，the joint dimension and counterpart gap shall be checked.When the gap is larger than 4mm，the counterpart gap shall be reduced by using a lateral surfacing method；and when the gap is 3mm-4mm，the mark shall be made，and the gap shall be subject to smooth transition in the course of welding.

2　The positioned welding of the weld should be conducted outside the bucket wall.When the plate thickness is less than 50mm，the length of the welding seam should be 50mm-100mm，the space should be 200mm-300mm，the distance to the crossed joint should be 150mm-200mm，and the height of the positioned welding should be 5mm or not exceed 2/3 of the plate thickness；and when the plate thickness is larger than 50mm，the length of the positioned welding should be 300mm-400mm and the space should be 300mm-800mm.The process and quality of the positioned welding shall be the same as those of the formal welding.The two ends of the welding seam shall be in smooth transition.The appearance quality shall be checked after positioned welding，and the relevant requirements of the design document or the current national standard GB 50372 Code for Installation Acceptance of Metallurgical Machinery Ironmaking Equipment Engineering shall be met.

3　The welding shall be conducted by methods of"multilayer and multi-weld beads，back-step welding，and continuous welding in each seam".Every 400mm-500mm of the fractional length of the welding seam shall be seemed as one section and the interlayer joint shall be staggered above 50mm.

4　The vertical weld of the charging bucket shall be welded by a method of synchronously welding through one-person and one-weld.The upper and lower ends of the vertical weld shall be reserved with 150mm-200mm.There shall be at least 3 welders for welding the ring weld，in addition，the welders shall be uniformly distributed in circle for welding.

5　For air gouging and back gouging of the outside joint，the depth shall be limited by gouging the defects of the weld root，the width shall not affect the welding electrode manipulation，and the straightness and depth shall be consistent.

6　The flanged joint may be welded by alternately manipulating electrode and shall be subject to ultrasonic testing after welding and polishing.

7　The internal quality of the butt weld of the charting bucket at the furnace bottom shall meet the requirements of the design document.The internal quality of butt weld shall meet the requirements of current national standard GB 11345 Method for Manual Ultrasonic Testing and Classification of Testing Results for Ferritic Steel Welds related to ClassⅡof Category B when there is no requirement in the design document.

8.5.3　The pressure test of the charging bucket shall meet the following requirements:

1　The pressure test of the charging bucket shall meet the requirements of the design document.When there is no requirement in the design document，the test pressure shall be 1.15 times of the design pressure.The water and air shall be used for the pressure test at the same time.The height for water injection shall be lower than the upper seal valve.

2　Before pressure test，the seal valve and the discharging mouth of the charging bucket shall be closed，air shall be used for pre-pressure test，air inlet valve shall be on to enter the compressed air，and the pressure shall be rose to 0.02 times of the test pressure and kept for 10min or determined according to the demand of leak detection.The foaming agent shall be painted on the welds and the flanged joint for check，and various parts shall be free of leakage.

3　The air in the charging bucket shall be exhausted and the water shall be charged to the level below the seal valve.

4　The inlet valve shall be on to enter the compressed air to the test pressure.The pressure shall be kept for 10min and then reduced to the working pressure.The pressure stop time shall be determined according to the demand of leak detection.The foaming agent shall be painted on the upper weld of the charging bucket and the flanged joint for check，and various parts shall be free of leakage.As a result，the pressure test is qualified.

5　The connection of the test unit and its accessories may be adopted according to the requirements of Appendix C of this standard.

8.5.4　The installation of the charging bucket shall meet the following requirements:

1　The longitudinal and transverse centerline of the base of the loading sensor of the charging bucket shall be centered by hanging the steel wire and the pendant，and their allowable deviation is 5.0mm.The elevation and mutual height difference of the upper surface of the base of the loading sensor shall be checked by the levelling ruler，the leveling instrumentor level gauge，and their allowable deviation is±5mm and 1.0mm respectively.

2　After centering，the base of the loading sensor shall be placed behind the simulation part as high as the sensor，and the charging bucket shall be installed in place.

3　The upper flange face of the valve box shall be placed with the filling（padding）on the flange as stipulated by the design document，and shall be connected with the lower flange of the charging bucket under the free status of the valve box and fastened by the connecting bolts.