I would like to ask what special requirements exist in design and manufacturing when reinforcing large openings?

Stress analysis should be conducted during the design phase, and smooth transitions should be achieved during manufacturing to reduce stress concentration.

So what are the main criteria that are cited?

The methods for strengthening openings in pressure vessels can be roughly classified into the following types based on their design approaches: 1. Equal area method–regular design (GB 150); 2. Pressure area method–HG 20582-1998 (opening ratio ≤ 0.8). But at this time, it is best to keep the opening ratio within the range of ≤0.7, as the Standards Committee has issued a notice stating that when using HG 20582-1998 for calculating reinforcement due to openings, only opening ratios ≤0.7 are accepted. 3. Limit analysis method 4. Stability analysis 5. Other methods: such as the experimental stress analysis method, and the use of incremental plasticity theory to study container openings and their reinforcement. Reinforcement structures can be classified as follows: 1. Reinforcement ring lap-welded structure 2. Integral reinforcement structure. As for manufacturing, the relevant manufacturing standards should be followed strictly in accordance with the requirements specified in those standards. However, regardless of the manufacturing standards, there are two principles that can be followed: 1. Full penetration of the structure ； 2. Smooth transition of the weld seam. Also, when the pressure is high, try to use an overall reinforcement structure. Personal opinion, for reference only!

GB-150 1. Equal-area method–regular design (GB 150) 6 J" Z; l8 L! K 2. Pressure-area method–HG 20582-1998 (porosity ≤ 0.8). But at this time, it is best to keep the opening ratio within the range of ≤0.7, as the Standards Committee has issued a notice stating that when using HG 20582-1998 to calculate reinforcement for openings, only opening ratios ≤0.7 are accepted. 0 b7 a6 A% k% u- m4 B u" a3. 3. Limit analysis method: 0 x8 Q6 Z+ d( E. J r4. 4. Stability analysis: ‘ E% U/ U2 _) V; X! ], E1 P5. 5. Other methods: such as the experimental stress analysis method, and the incremental plasticity theory method for studying container openings and their reinforcement, etc. # C; a5 R# p0 A) }9 C$ l. Reinforcement structures can be classified as follows: : Y( O/ P# Z2 H4 p4 a8 Z7 k7 } 1. Reinforcement ring lap-welded structure: % n/ x5 t# L: i) y0 E2 ^# I. q7 i2. 2. Integral reinforcement structure: & u `' T3 f9 j0 A%. Regarding manufacturing, the relevant manufacturing standards should be followed strictly in accordance with the requirements specified in those standards. However, regardless of the manufacturing standards, there are two principles that can be followed: 1. Full penetration of the structure ； 2. Smooth transition of the weld seam. Also, when the pressure is high, try to use an overall reinforcement structure. 0 ?9 D- p; j4

Pressure area method--HG 20582-1998 (porosity ≤ 0.8). But at this time, it is best to keep the opening ratio within the range of ≤0.7, as the Standards Committee has issued a notice stating that when using HG 20582-1998 to calculate reinforcement for openings, only an opening ratio of ≤0.7 is accepted; the pressure area method is not recognized by the Standards Committee. The exact wording is: “The mathematical model principles for reinforcement of openings based on the AD standards are in conflict with China’s safety margin requirements.” Although there were no safety issues, this does not mean that the requirements are met. It is recommended to conduct stress analysis calculations when d/D > 0.7, and to evaluate the strength in accordance with JB4732-95. ”

First of all, thank you all for your excellent answers. The design primarily takes reference from model 150. What are the additional requirements regarding the manufacturing, non-destructive testing, and acceptance of areas with large openings? Please let me know

Should a factor of 1.5 or 3 be used for the general assessment in the analysis and design of large openings?