The connection joints of various components of the high-voltage transmission line tower can be fastened and welded only after passing the inspection.
The connecting bolts of the tower column, cross bar, diagonal bar and the main beam of the tower must be perforated, and 2% of the secondary parts are allowed not to be perforated, but must be repaired by electric welding. The welding strength is equal to the strength of all the bolts at this node. For high-strength bolts, the strength shall be equal to the missing bolt. During temporary connection, bolts, nuts and nuts shall not be less than one-third of the total number of installation holes.
The flange plate of the tower column of the high-voltage transmission line is locked with double nuts, especially the embedded bolts of the tower shoe and the foundation. Other bolts shall be locked with spring washers, and the bolt insertion direction shall be consistent and reasonable. After fastening, the exposed length shall be 2~3 threads.
Tighten the flange bolts symmetrically according to the angle distributed around the circle. The node bolts shall be tightened symmetrically from the center to the edge.
The connecting bolts of the tower column, cross bar, diagonal bar and the main beam of the tower must be perforated, and 2% of the secondary parts are allowed not to be perforated, but must be repaired by electric welding. The welding strength is equal to the strength of all the bolts at this node. For high-strength bolts, the strength shall be equal to the missing bolt. During temporary connection, bolts, nuts and nuts shall not be less than one-third of the total number of installation holes.
The flange plate of the tower column of the high-voltage transmission line is locked with double nuts, especially the embedded bolts of the tower shoe and the foundation. Other bolts shall be locked with spring washers, and the bolt insertion direction shall be consistent and reasonable. After fastening, the exposed length shall be 2~3 threads.
Tighten the flange bolts symmetrically according to the angle distributed around the circle. The node bolts shall be tightened symmetrically from the center to the edge.
For bolts under tension and dynamic load, effective measures must be taken to prevent loosening after fastening, such as double nuts on anchor bolts.
When the high-voltage transmission line tower is connected with fixed bolts, one end of each bolt shall not be padded with 2 or more washers, and large nuts shall not be used to replace washers. The exposed length after fastening the bolts shall not be less than 2 threads. Do not use gas to cut the bolt hole.
When welding the weld, ensure that the welding environment is in good condition. If the following conditions occur and no effective protective measures are taken, the weld shall not be welded:
Strong wind, wind force greater than or equal to 10m/s (level 5)
Relative humidity: above 90%
Welders must have job qualification certificates. Personnel without work certificate shall not engage in this type of work.
Before welding each layer of weld, the slag and splash of the previous layer shall be removed, and the sparks in each layer of weld shall be staggered. For places with concentrated welds, welding shall be carried out in strict accordance with the method and sequence specified in the welding process.
Welding. The external dimensions of welded joints shall comply with the standard External Dimensions of Welded Joints of Steel Structures.
Closed welding shall be adopted for splicing of floor and partition to avoid water leakage.
The welds at the welding site shall be inspected by level, and the inspection method can be weld gauge or nondestructive testing instrument. During inspection, carbon steel welds shall be cooled to ambient temperature, and alloy steel shall be welded.
It can only be carried out after 24 hours. The welding surface shall be free of cracks, welding marks, pores, slag inclusions, arc scratches, undercuts, incomplete welding, root shrinkage and other defects. Welders are not allowed to handle cracks during welding,
Find out the cause, formulate the repair process, and then deal with it. The number of weld repairs at the same position shall not exceed 2.
After the installation of the tower body structure of the high-voltage transmission line, the overall measurement and correction shall be carried out, and all the data shall meet the requirements of the acceptance specification. After correction, use torque wrench to check whether all bolts are fastened.
HENGFENGYOU ELECTRIC GROUP, is an electrical enterprise with transmission and distribution industry as its main business, integrating product research and development, manufacturing and trade. Designated suppliers for the world's top 500 enterprises .Its main products include power transformers, medium and low voltage switchgear, distribution panel ,circuit breakers, transmission tower ,Cable and other power distribution equipment , HENGFENGYOU ELECTRIC GROUP has been working hard to provide the best transmission, distribution solutions for users all over the world. www.transmission-tower.com ; sales@hengfengyou.com ； WhatsApp：+86158 5325 2696（Jack）