How many types are there for opening reinforcement of pressure vessels? What regulations should be followed when using a reinforcing ring structure for reinforcement?

The methods for strengthening openings in pressure vessels, classified by design approach, are roughly as follows: 1. Equal area method； 2. Limit analysis method ； 3. Stability analysis ； 4. Other methods, such as experimental stress analysis, and the use of incremental plasticity theory to study container openings and their reinforcement, etc. Based on the reinforcement structure, its basic structures can be roughly divided into two categories: 1. Reinforcement ring lap-welded structure ； 2. Overall reinforcement structure. When reinforcement is carried out using a reinforcing ring structure, the following rules shall be followed: 1. The standard tensile strength of the steel material used at normal temperature, σb, shall be ≤ 540 MPa ； 2. The thickness of the reinforcement ring is less than or equal to 1.5δn ； 3. The nominal thickness of the shell δn ≤ 38 mm. If conditions permit, it is recommended to use thick-walled pipes instead of stiffening rings for reinforcement.

Very comprehensive; the original poster deserves extra points

Do all openings need reinforcement?

The shell or pipe itself can be reinforced; it is not necessary to use reinforcement rings