Effective thickness of flange
Thread Content
As shown in the figure below, when SW6 calculates non-standard flanges, the effective thickness of the flange is 30mm, 29mm； 25mm or 24mm?
Generally, the depth of the structural groove must be deducted.
Does this meet the requirements for usage intensity?
One of the stress-bearing parts of the flange is the bolt hole and the other is the sealing ring. The two forces are equal in magnitude and opposite in direction. They are a pair of balanced forces. The sealing ring is the thinnest. So the effective thickness should be 25
As stated in HG/T20592
The method to judge the flange thickness is the total thickness starting from the DG action point and removing the structural thickness. The flange thickness in the picture is 25mm.
Looking for basis or standard screenshot, 20592 only mentioned the flange thickness, but what needs to be input in sw6 is the effective thickness of the flange. According to the flange design rules, the flange is divided into three parts, bolted ring + tapered neck + shell； The most critical part is the calculation of the bolt ring ； Therefore, some people think that the effective thickness of the flange should be calculated by changing the thickness of the bolt ring.
Looking for basis or standard screenshot, 20592 only mentioned the flange thickness, but what needs to be input in sw6 is the effective thickness of the flange. According to the flange design rules, the flange is divided into three parts, bolted ring + tapered neck + shell； The most critical part is the calculation of the bolt ring ； Therefore, some people think that the effective thickness of the flange should be calculated by changing the thickness of the bolt ring.
If it can be determined that the maximum stress is at the bolt ring, it is reasonable to use the bolt ring thickness to check the flange stress. However, it is not known where the maximum stress is before determining the calculation coefficients related to the size of the flange structure, so it is still necessary to be conservative and deduct the depth of the ring groove. If the design believes that there is basically no corrosion at the gasket, the corrosion allowance caused by the working medium does not need to be deducted.