What are some common design errors in pressure vessels?

I. Major Technical Errors (Endangering Safety)
These errors can cause serious safety hazards and potentially significant economic losses:

1. Incorrect classification of pressure vessels, leading to mismatched application of standards;

2. Incorrect strength or stiffness calculations for major pressure-bearing components (shell, heads, flanges, etc.), with significant discrepancies between drawing parameters and calculation sheets;

3. Incorrect material selection for major pressure-bearing components, failing to meet the requirements of the medium, pressure, and temperature conditions, a typical technical error;

4. Omissions or errors in important technical requirements, with fundamental errors in the structural design of major pressure-bearing components.

II. General Technical Errors (Potential Hazards)
Failure to meet standard requirements can cause certain safety hazards or cost waste:

1. Incorrect or omitted design parameters, incorrectly defining the jurisdiction of pressure vessels or classifying them too broadly;

2. Incorrect selection of materials and standards for pressure-bearing components, incorrect or omitted technical requirements;

3. Errors or omissions in strength calculations, and errors in drawing dimensions and data annotation.

III. General Drawing Errors (Affecting Machining) These do not pose safety hazards but will affect manufacturing:

1. Failure to use legally recognized units of measurement; use of easily confused letters (e.g., i, j, l, o) for pipe nozzle symbols, which may be misread as numbers;

2. Inappropriate selection of dimensional baselines; presence of closed dimension chains; omission/incorrect annotation of positioning dimensions for container accessories;

3. Incorrect or omitted selection of tolerances and roughness specifications; flange bolt holes not arranged across the center; incorrect or omitted pipe nozzle/support orientation;

4. Sectional drawings and detail drawings do not conform to drafting standards; contain textual errors, linear errors, and incorrect component part numbers.