Incorrect classification in pressure vessel review drawings

3. Classification of design errors 3.1 Technical errors: refer to major, principled errors. Due to these errors, serious difficulties will arise in areas such as material preparation, manufacturing, installation, production, and maintenance ； It will result in significant design rework ； It will cause safety accidents. For example: (1) It does not comply with relevant laws, regulations, norms, standards, and technical requirements, etc ； (2) Errors in the design basis data, calculation formulas, technical parameters used, or in the calculation results ； (3) The strength, stiffness, and stability of the equipment or its main components are insufficient ； (4) The structure is severely unreasonable. It is inconvenient for manufacturing, installation, transportation, maintenance, and operation; it hinders production, technical safety, and labor protection, resulting in significant waste ； (5) Incorrect selection of material for the equipment or its components ； (6) Incorrect selection of standard diagram, generic diagram, or reusable diagram ； (7) The absence of necessary technical requirements, instructions, notes, etc., or unclear or incorrect requirements, can lead to losses ； (8) Fails to meet process requirements, resulting in significant rework ； (9) Lack of necessary design documents, thereby affecting the issuance of drawings or construction ； (10) It does not comply with the unified regulations of the unit and the project. 3.2 General errors: These refer to carelessness in work that results in mistakes in the detailed aspects of the design; however, they have little impact on material preparation, manufacturing, installation, production, or maintenance, and do not lead to significant rework or losses and waste. For example: (1) Incorrect listing of drawing numbers or titles can result in drawings being sent incorrectly or missing ； (2) The drawings do not conform to mechanical drawing standards and relevant unified regulations, thereby directly affecting construction ； (3) Contradictions and inconsistencies in the drawings will cause difficulties or inconvenience during construction ； (4) The pattern or calculations do not match ； (5) Incorrect or missing numbers and units, missing part numbers, contradictions between overall dimensions and individual dimensions, inappropriate reference surface for dimensioning ； (6) The surface roughness, tolerance fits, geometric tolerances, heat treatment, etc. of general components are inadequately specified or the selected options are not suitable ； (7) The structure is not very reasonable, resulting in waste of materials and labor, as well as difficulties in processing ； (8) Incorrect standard numbers, specifications, or material selection for parts, or unclear markings ； (9) The technical requirements are incomplete or incorrectly specified, with missing necessary explanations ； (10) Significant error in equipment weight calculation (error before the decimal point of at least 20%). 3.3 Drawing errors: refer to errors resulting from poor drafting techniques or low quality in document preparation, but which do not affect manufacturing, installation, or production. For example: (1) Missing dimension lines, cross-section lines, leader arrows, and obvious dimension errors that do not lead to confusion ； (2) The part numbers are incorrect, and the quantity counts are wrong ； (3) Typos or unclear file descriptions, but without causing any misinterpretation ； (4) The sheet size and drawing scale do not meet the requirements; the scale of the drawings is unnecessarily enlarged, or the drawings are not clear enough ； (5) The projections and dashed lines are drawn incorrectly, and the layout of the diagram is highly uneven ； (6) Misuse of tags, incorrect tag names ； (7) The names, specifications, materials, etc. of the components in the details column do not match the corresponding standards, samples, or component drawings ； (8) Other drawing errors.

Refer to the book \"Pressure Vessel Design Management System\" published by the Chemical Equipment Association