Introduction of inspection system for high-strength bolt tightening

Today, the editor brings you the content of the high-strength bolt tightening inspection system. If you don’t know it well, come and find out! 1. After the final tightening of high-strength bolts, the on-site professional technicians should send the notice of final tightening test to the laboratory as soon as possible, and the laboratory must do all kinds of preparations before the final tightening test. 2. The on-site final tightening inspection must be carried out within 4H~24h after the high anchor bolts are tightened. The final screw inspection will be carried out by the experimental staff in the work area, and the on-site cooperation will be done. 3. The torque wrench needs to be calibrated before inspection, and the torque deviation should not exceed ±3% of the normal torque value. 4. The initial tightening inspection is carried out by on-site professional and technical personnel. Hit the opposite side of the nut with a hammer weighing about 0.3 kg, and firmly hold the opposite side of the nut with your fingers for inspection. If the vibration is relatively large, it is deemed to be unqualified, and the initial screwing should be carried out again. 5. Before the final tightening inspection, the on-site professional technicians should observe all the high-strength bolt joints after the final tightening, and check the relative positions of the anchor bolts and nuts marked with paint circles after the initial tightening, so as to check whether the final screwing is missed. screw. 6. The final tightening inspection frequency must be strictly in accordance with the specifications. At the junction of main truss beams, side beams, and load-bearing beams, the number of high-strength bolt connections for each anchor bolt group is 5%, but not less than 5 sets, and at least 1 set of tightening torque inspections is carried out for each connection point. 7. Finally, check the torque value of the nut after tightening. The error cannot exceed 10% of the torque value, otherwise it will not pass. 8. However, anchor bolts account for no more than 20% of the number of sampling inspections at each connection point. If it exceeds 20%, sample inspection will be carried out again until the total compliance rate reaches 80%. 9. When the tightening is not enough, it should be made up as soon as possible. When the tightening is too much, the anchor bolts should be replaced and tightened again. 10. During the whole inspection process, the test staff must make original records of the test and file them on time. 11. After the test is completed, the laboratory should directly publish the relevant data information.