Drawing verification – what exactly is being verified?
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Construction drawings – what are they? Drawings that are given directly to workers so that they can use them as a guide for construction should be called construction drawings. Regarding the drawings produced, I think: 1. For the part drawings, there are no errors in the dimensional data shown, meaning the drawings are clearly presented ； 2. Assuming there are no errors in the graphic dimensions, strive to achieve an aesthetically pleasing layout on the drawing ； 3. As for component diagrams, or part diagrams, as to which parts should be placed on the same drawing, or which parts can form one component, I believe it should be determined based on the manufacturing process. Take a bicycle wheel as an example: the entire wheel can be considered one component, which can be fixed to the frame using axle bolts; the tire, spokes, and rim can also be regarded as one component. 4. For the general layout, it should be sufficient to clearly indicate the dimensions of the key areas ； Of course, for textual elements such as technical requirements and specification sheets, those that are necessary must not be omitted. ————————————Regarding the representation of boundaries on drawings: some people prefer to use C3, C2 to indicate chamfers, while others use 1×45° for that purpose. Some use δ6 to represent thickness, and others use t=6. I wonder if anyone among you has ever been corrected when drawing? It was written as C3, but it was crossed out after verification and changed to 3×45°; have you had a similar experience? I have some questions regarding this: 1. In the same assembly drawing, for the same component – for example, when indicating its elevation – should it be marked in views from different directions as well? 2. In the same assembly drawing, for the same part that has a detail view provided, should it be labeled in both the main view and the detail view?
Verification mainly focuses on the design conditions, calculation sheets, and dimensions in the drawings. Using one's own design drawings is one approach.
With so many designs to be checked and reviewed, why not let everyone share their opinions?
1.1 In the same assembly drawing, for the dimensions of the same part, it is sufficient to indicate them clearly and completely; there is no need to repeat the markings. For example, regarding height, if it is indicated in the front view, there is no need to indicate it in the side view ； Otherwise, it will be very troublesome to make adjustments to the images later on, and inconsistencies in dimensions are likely to occur.
2. In the same assembly drawing, for the same part, if there is a detail view available, any information that can be clearly shown in the front view should be indicated there; information that cannot be shown clearly should be indicated in the detail view. Do not indicate the same information repeatedly. Generally, when drawing a partial diagram, it is mainly to clearly show the changes in relative positions.
The main task is to check the drawings to identify any areas that are not clearly expressed, any errors, and whether they violate the basic principles of design, etc. No one is perfect, so it’s impossible for a drawing to be error-free. Multi-level review is very necessary. In the same assembly drawing, suggestions regarding the elevation and dimensions of the same component should be indicated only in one place; indicating them in multiple places makes it easy to overlook changes later on. There is a local diagram, and annotations can be made on it to make the expression clearer. Personal opinion, for reference only.
The points made on floors 5, 6, and 7 are valid; the same part doesn’t need to be labeled in multiple places. Verification is more thorough than inspection, as it requires checking every dimension and every piece of data, while inspection only looks at the key points.
This post was last edited by SDHZZXM on 2017-7-13 09:26. The design agency should have a design technical specification that contains regulations regarding this matter. Or in the procedural documents of the system documentation.
The drawings serve as the basis for manufacturing. For pressure vessels, the drawings include assembly drawings, component drawings, part drawings, material lists, catalogs, etc. During verification and review, in addition to the drawings, it is also necessary to examine the calculation documents (for strength and manufacturing processes), risk assessments (of three types), operation and use instructions, engineering technical specifications, as well as information regarding the position of pipe connections and foundations provided by the main design institute. When reviewing drawings, the basis for their design must first meet relevant standards such as those set by industry bodies and companies; secondly, it is necessary to check whether the specific dimensions and visual representations in the drawings are accurate, whether the proposed technical requirements are appropriate, and whether they satisfy the manufacturing requirements. It is necessary to master knowledge of current standards, design, materials, non-destructive testing, welding, manufacturing, heat treatment, etc.
HG/T20701 \"Regulations on the Management of Professional Projects for Containers and Heat Exchangers\" specifies in detail that the quality system documents of pressure vessel design units must also include detailed rules regarding review processes.