The disassembly of vacuum clamp joints is a controlled process of mechanical energy release, and its technical core lies in the reverse restoration of the interface stress field established during assembly. The starting point for disassembly must be the first bolt on the diagonal of the clamp locking bolt, which is unloaded in five stages according to the torque attenuation sequence specified in ISO 2852: the first stage is reduced to 70% of the specified torque, the second stage is reduced to 40%, the third stage is reduced to 15%, the fourth stage is reduced to 5%, and the fifth stage is completely loosened - this sequence ensures that the clamping force is uniformly attenuated along the circumference of the flange, avoiding uneven elastic recovery of the sealing ring caused by sudden stress release on one side. Non metallic blunt tipped tweezers (with a curvature radius of ≥ 0.3 mm at the top) must be used to remove the sealing ring. Vertical force should be applied from the side wall of the groove, and lateral prying is prohibited to prevent shear tearing of the FFKM material (which has a fracture elongation of only 180-220%). When separating flanges, the parallelism between the two planes must be maintained at ≤ 0.01 mm/m. A dial gauge should be used to monitor the change rate of end face clearance in real time. If the increase rate of single-sided clearance is greater than 0.005 mm/0.1 mm stroke, stop immediately and recalibrate the alignment. After disassembly, the flange sealing surface must be immediately covered with a PTFE protective film with a thickness of 0.05 mm and a surface hardness of ≤ 20 Shore A to prevent suspended particles (>0.3 μ m) in the air from settling and forming a hard scratch source. The old sealing ring needs to undergo infrared spectroscopy (FTIR) analysis to detect the main chain fracture peak (1720 cm ⁻¹) and changes in crosslinking density. If the carbonyl index is greater than 0.25, it is determined that it cannot be reused. All dismantling operations must be carried out in dry air with a dew point of ≤ -40 ℃, and the environmental humidity should be controlled at RH ≤ 25% to avoid the formation of electrochemical corrosion micro cells on the metal surface due to moisture.