Insulation material for back-pressure turbine casings

Blankets made of magnesium aluminum silicate or ceramic fibers can also be used; they are reusable and easier to install and remove than those made from rare earth materials.

Composite siliceous rock paste with a density of less than or equal to 160 kg/m3 can be used ； Thermal conductivity: 0.38–0.056 W/(m·K) ； With a operating temperature of 800°C, here is another set of technical requirements for equipment and pipeline insulation, which might be useful to you. Technical requirements for insulation of equipment and pipelines: In accordance with current **standards and industry practices, the following requirements are set for the insulation and protective layer structures of equipment and pipelines: 1. The thickness of the insulation layer on equipment and pipelines shall be calculated by the construction party using the insulation materials specified by the client, and approved by the project supervisor. 2. Before insulating the equipment and pipelines, the primer and topcoat on their supports and hangers must be applied, and the primer on the equipment and pipelines themselves must also be applied. 3. During insulation, temperature sockets, thermal sampling points, junction boxes, thread plugs, and nameplates on the equipment and pipelines should be left exposed, taking care to avoid any damage to them. 4. Equipment and pipelines are covered with galvanized iron sheets as a protective layer (cylinder insulation is excluded). 5. At the areas of the pipeline insulation near valves and flanges, end caps made of the same material as the protective layer should be added. 6. Before insulating vertically installed pipes, brackets should be installed to prevent the insulation from sinking; these brackets are generally placed every 2 to 3 meters. 7. The insulation layer should be applied in layers, with the joints between the inner and outer layers offset from each other. There should be no voids between the layers or at the joints. The insulation material must adhere tightly to the equipment and pipes, and no cracks should appear on the surface of the protective layer after it is applied. 8. The insulation layer of the lower cylinder should be thicker than that of the upper cylinder. 9. The flow direction arrows for the pipeline medium shall be painted in accordance with relevant regulations, and their color, size, and style shall be determined as per the client’s requirements. 10. During the insulation process, the construction unit must undergo inspections by the supervisor and the client, and approval from the supervisor must be obtained before applying the protective layer. 11. The insulation for valves adopts a detachable valve box design, which facilitates disassembly and ensures an attractive appearance; valve identification tags are installed at designated locations. 12. The galvanized iron sheet protective layer shall adopt a rivet structure; self-tapping screws are not allowed, and the spacing between rivets shall not exceed 150 mm. 13. After insulation is completed, galvanized iron sheets should be added as soon as possible to prevent dust accumulation or moisture on the insulation surface, which could affect its insulating efficiency. 14. After the installation of the galvanized iron sheet protective layer is completed, proper protection of the finished product must be ensured; any damage that occurs before the project is handed over is the responsibility of the construction party. 15. After the insulation work is completed, it is necessary to conduct actual measurements to verify the surface temperature of the insulation layer as well as its heat dissipation rate. The acceptable standard for the surface temperature of the insulation layer is: 44 degrees for cylinders and main steam pipelines℃ ； Primary and secondary extraction steam 40℃ ； Third and fourth stage extraction steam 36℃ ； Feed water temperature: 34°C. The surface heat dissipation density of the insulation layer is shown in the attached table: 16. Matters not covered herein shall be handled in accordance with the drawings provided by the power design institute and **relevant standards. Turbocharger Technical Renovation Project Team Appendix: Maximum allowable heat dissipation density on the outer surface of the insulation structure. Temperature (°C), normal operating conditions: w/m2. Temperature (°C), normal operating conditions: w/m2. 100: 58; 300: 186; 150: 116; 350: 209; 200: 140; 400: 227; 250: 163; 450: 244. “Code for Construction and Acceptance of Insulation Works for Industrial Equipment and Piping” GBJ126-89 (excerpts). Chapter 1 General Provisions. This code applies to the construction and acceptance of external insulation works where the temperature range of the medium is greater than or equal to -196°C and less than or equal to 850°C. Chapter 2 Materials Section 1 Quality Requirements §2.1.1 The quality of insulation materials shall meet the following requirements: 1. The insulation material must have an equation or chart showing its thermal conductivity as a function of temperature. For insulating materials and their products used as thermal insulation layers, when their average temperature is less than or equal to 623 K (350°C), the thermal conductivity value shall not exceed 0.12 W/(m•K); for insulating materials and their products used as cold insulation layers, when their average temperature is less than 300 K (27°C), the thermal conductivity value shall not exceed 0.064 W/(m•K) [0.055 Kcal/(m•h•°C)]. II. For insulation materials and products used as thermal insulation layers, their bulk density shall not exceed 400 Kg/m3; for insulation materials and products used as cold insulation layers, their bulk density shall not exceed 220 Kg/m3. III. For rigid insulating materials used for thermal insulation, their compressive strength must be at least 0.4 MPa (4 Kgf/cm2); for those used for cold insulation, the compressive strength must be at least 0.15 MPa (1.5 Kgf/cm2). IV. Insulating materials and products must come with data or specifications regarding their flame resistance, expansion properties, and moisture resistance, and they must meet the requirements for use. V. The chemical properties of insulating materials and their products should be stable, and they should not have a corrosive effect on metals. VI. Bulk insulating materials used in filling structures must not contain any impurities, sediment, or dust. In fiber-based insulating materials, the proportion of slag particles with a size of 0.5 mm or more should be: less than 10% for slag wool, less than 6% for rock wool, and less than 0.4% for glass wool. Porous granular insulation materials with a diameter of less than 0.3 mm are not suitable for use. §2.1.2 Quality of moisture-proofing layer materials §2.1.3 Quality of protective layer materials Section 2 Quality inspection §2.2.1 Insulating materials and their products must be accompanied by a product quality certificate or a factory approval certificate, and their technical specifications and performance requirements must comply with those specified in the design documents. §2.2.2 When the indicators listed in the product quality certificate or factory inspection certificate for insulating materials and their products are incomplete, or if there are doubts regarding the product quality, the supplier shall retest the relevant properties and submit a test certificate confirming compliance. §2.2.3 When rechecking materials and products used for moisture protection and protective coatings, it is necessary to ensure that their dimensions are within the specified limits and free of defects; sampling tests should be conducted to verify that parameters such as tensile strength, compressive strength, bulk density, water vapor permeability, heat resistance, and cold resistance meet the **specified requirements.