Specific provisions for material substitution
The specific provisions of material substitution are often difficult or difficult to consider and analyze in the design and manufacture of equipment. Material substitution is widely used in the design of pressure vessels. The "Safety Technical Supervision Regulations for Stationary Pressure Vessels" has clearly defined the substitution of pressure vessel materials. In its design and manufacture, the main requirement is to select not only the materials of the pressure-bearing components of the pressure vessel but also the materials to be replaced. The shape quality is similar, and the chemical composition, size standard, performance index and monitoring method of the material should be fully considered for reasonable substitution. The most basic principle of material substitution is to eliminate the application of various indicators that do not meet the standard materials in the substitution, strictly ensure the quality of the materials and achieve absolute guarantee, the technical requirements of the technical substitute materials can not be lower than the substitute materials, and can pass many Material selection methods are used to test and test materials.
The formalities for the substitution of materials are:
(1) The substitution of the pressure-bearing parts of the container shall be strictly carried out, and the re-inspection report or quality certificate of the substitute materials shall be submitted and approved by the technical department of the substitute unit, and approved by the person in charge of the competent authority;
(2) The material substitution must be made at the time of manufacture of the pressure vessel after obtaining the permission of the original design unit and obtaining the supporting documents;
(3) The specification part, material and specifications of the substitute material shall be carefully marked in the design drawing, construction drawing and quality certificate of the factory.
