Large and medium-sized in the 21st centuryFlangeIn the chemical plant, oil refinery industry, high pressure vessel is one of the key machinery and equipment. high pressure vesselFlangeThe port is the only way for the throughput of raw materials. It is the port for connecting other equipment. The tightness test of the connection seal of the high-pressure vessel is each.FlangeThe mouth must be long-term to ensure.FlangeThe whole process of compaction between the inner hole seal groove and the gasket, the compaction level and the uniform level of compaction on the circle all cause immediate harm to the tightness. A key element that endangers the actual effect of the seal is the loading process of the preload of the bolt and the size of the preload.
The flange preload bolt connects the gasket andFlange. For the flange sealing place of octagonal gasket or oval gasket, in terms of process, it is rightFlangeThe extensive provision for pre-tightening bolts is to gradually load on the circle so that the gasket is gradually evenly placed.FlangeSealing groove to ensure that the gasket does not produce partial deformation; the pre-tightening force of each bolt to achieve the standard value. For the tightening process of this kind of bolts, the process selected at this stage is to use a torque wrench to complete the loading, and the torque value displayed by the torque wrench is indirectly calculated to match the pre-tightening force of the bolt.
This kind of torque method can visualize the safeguard measures, accurate measurement is very easy, the operation process is simple, and the management procedure is simple. However, it cannot take into account such factors as the friction resistance effect between various components and the incomplete friction resistance in bolt components, so that the dispersion of the pre-tightening force is large, and the process regulations of the whole process of symmetrical pre-tightening cannot be reliably guaranteed. Therefore, the linearity is low, which is very harmful to the actual effect of the connection flange seal, and immediately endangers the long-term, reliable and smooth operation of the machine and equipment.