ISO 12671:2021 pdf free download.Thermal spraying – Thermally sprayed coatings – Symbolic representation on drawings.
1 Scope
ISO 12671 specifies how the symbolic representation of thermally sprayed coatings is indicated on
drawings.
2 Normative references
There are no normative references in ISO 12671.
3 Terms and definitions
No terms and definitions are listed in ISO 12671.
ISO and IEC maintain terminological databases for use in standardization at the following addresses:
4 General
Coatings may be indicated with the general recommendations for technical drawings. To apply this symbolic representation will make sense in cases where the thermally sprayed coating is very thin and/or can be built up by several dissimilar coatings one upon another.
The symbolic representation shall clearly give all the necessary indications regarding the specific coating to be obtained without over-burdening the drawing with notes or showing an additional view or detail enlargement.
This symbolic representation includes an elementary symbol and one or more supplementary symbols and further complementary indications.
If a large number of instructions for producing the coating have to be mentioned, it is recommended to indicate the specific instructions on the drawing or to define them in a separate parts’ list, if applicable (see Figures 6 and Z).
5 Symbols
The elementary symbol shall indicate that this process deals with thermal spraying.
The following information shall be given by supplementary symbols:
— type of coating (bond or top coat);
— the spraying process and subsequent treatments.
The following requirements may be defined by further additional instructions:
— the coating thickness needed or the final coating thickness machined;
— the spray material to be used;
8 InstructIons when using a separate parts’ list
This clause applies when a component is represented by one or more drawings and a separate parts’ list. In such a case, the coating will be indicated on the drawing only by a position number (see Figure 6). Any instructions regarding the coating, such as the spraying process. coating thickness and its acceptable thickness deviation (especially ii coatings consist of a bond and top coatj, spray material. surface condition and post-treatments shall be defined in the parts’ list or by indicating a specific technical instruction (see Figure 6).
9 InstructIons when the use of the spray process is protected by a patent
If a coating process shall be applied but the use is protected by a patent (spraying procedure, spray material, process parameter, etc.). the trade name of this coating process may be Indicated analogous to “Coating per special specification” (see Figure 7) as a supplementary symbol in the symbolic representation, or it may be defined via a position number in the pertinent parts’ list (see Figure 6).
10 Representation and dimensioning
The area of a component to be coated shall be indicated by a broad dashed-dot-line outside the outline of the component on the drawing. Where necessary, the size and position of the range of coating shall be defined by means of dimensions and tolerances on the drawing.
Areas that are allowed to be coated (e.g. outside the coating range) shall be indicated by a broad dashed line outside the component’s outline.
Areas that are not accepted to be coated shalt not be indicated (see Clause 11).
The dimension that locates the coating In relation to the front face of the work piece shall appear on the drawing only.
The dimensions of length and/or width shall appear on the drawing only.
Whenever a post-treatment is applied, the indication of the roughness tolerances shall be mentioned corresponding to the pertinent standard on the drawing close to the dimension.
Instructions regarding coating thickness or thickness of the bond and top coat are to be indicated together with further instructions in the symbolic representation or in the parts’ list. The coating thickness shall apply for the indicated condition (e.g. as = as sprayed. I = fused. rn/c = machined, or in combination: f.m/c = fused and machined).
II no further instructions about acceptable deviations of coating thickness are mentioned, the general tolerances shall apply.
11 Supplementary Instructions
Supplementary instructions may be necessary to define further particular characteristics by indicating them either In the symbolic representation or In a separate parts’ list.
Instructions containing specific instructions for the execution of the preparation or spray procedure or thermal treatment or special sealing are preferably indicated behind the elementary symbol for the
thermally sprayed coating with the pertinent specification number, or they will he indicated by their position number In the parts’ list (see Elgurel and Tahhi.1).
For workshop drawings only, a remark for applying masking may be given by a specific sign on areas that are not allowed to be coated (see Figure S).
A remark restricting the acceptable deviations from the nominal thickness shall be added to the coating thickness on the drawing, in the parts list or as part of an individual specification.
12 Examples
Figures.2 to 6 show examples of the symbolic representation of thermally sprayed coatings. Figure 7 shows the designation for a thermally sprayed coating by using a position number. The technical Instructions for the thermally sprayed coating shall be defined In the parts’ list.