Visual Inspection and Alignment Check
Coaxiality Check: The deviation between the clamp's central axis and the pipeline's central axis is ≤2 mm/m; the two shell halves are perfectly aligned with no skewing or misalignment.
Coverage Check: The leak point is centered within the clamp's inner cavity; the sealing gasket fully covers the leakage area, extending 5–10 cm beyond the original leak point.
Shell Gap Check: The flange gaps on both sides of the upper and lower shells are uniform, with no unevenness (i.e., wider on one side and narrower on the other).
Bolt Tightening Verification
Exposed Thread Length Check: All bolts fully penetrate the flange holes, with at least three thread pitches exposed beyond the nut to ensure adequate tightening strength.
Torque Verification: Following a diagonal, multi-step tightening sequence, all bolts meet 100% of the design torque specifications; load distribution is uniform across all bolts, with no instances of localized overtightening or looseness.
Absence of Abnormal Deformation: The clamp shell shows no cracking or deformation caused by excessive tightening force, and the flange faces are in full contact with no edge warping.