Inspection Before Countersunk Carriage Bolt Delivery » Discussions


Inspection Before Countersunk Carriage Bolt Delivery

  • Leader
    Feb 9

    1. Perform a general survey of high-strength bolts with a small hammer to prevent leakage.

    2. The inspection quantity shall be 10% of the number of Countersunk Carriage Boltat each node, and shall not be less than 10, but no less than one for torque inspection.
      3. During inspection, draw a line at the relative position of the end of the screw and the nut, return the nut to about 60 degrees, and use a torque wrench to measure the torque value returned to the original position. The deviation between the torque value and the construction torque value is within 10%. If any non-compliance is found, the inspection should be expanded by 10%. If it still fails, the high-strength bolts of the entire joint should be re-tightened. The measured torque at this time should be in the range of 0.9Tch ---- 1.1Tch. (Calculate Tch = k × p × d according to the following formula; k: average torque coefficient of high-strength bolt connection pair p: pre-tension of high-strength bolt construction d: diameter of high-strength bolt screw)
      4. If any non-compliance is found, the inspection should be extended by 10%. If there are still unqualified persons, the high-strength bolts of the entire joint should be tightened again.

    3. High-strength bolted joint torque check should be performed within 24h after the bolt is finally tightened.


    6.Sampling inspection of bolts


    In conclusion, the above-mentioned prevention method is used for random inspection of the high-strength bolts. After the random inspection is completed, the nut is marked with another color.


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