Technical requirements and quality standards for wear-resistant elbows of pulverized coal pipes of coal mills
1.Type: Ceramic patch wear-resistant pipe fittings.
2.Quantity: wear-resistant elbow, 45°(r=1000mm l1=200mm l2=300mm 762*10mm): 10 pieces;Wear-resistant elbow, 90° (r=1000mm l1=200mm l2=300mm 762*10mm): 24 pieces.
All pipe fitting drawings are provided by the bidder.
3.Specific requirements for pulverized coal pipe elbow of coal mill:
3.1. The design, manufacture, inspection, testing and packaging of this equipment shall conform to the current national standards, industry standards and other relevant standards.
3.2. Meet the requirements of the design drawings of the electric power design institute for the wear-resistant pipeline system.
3.3. The equipment performance of the pulverized coal pipe elbow should meet the design and use requirements of the powder feeding pipe fittings of the 660MW thermal power generating unit pulverizing system.
3.4. The design, manufacture and technical performance, chemical composition, physical properties and packaging and transportation of pulverized coal pipe elbow conform to the People's Republic of China electric power industry standard DL T690-2015 "Technical Conditions for Wear-resistant Pipelines".
3.5. The design of the elbow of pulverized coal pipe should meet the requirements of anti-wear, anti-vibration, anti-shedding, anti-powder accumulation and good weldability.
3.6. The bidder shall be responsible for the technology and quality of the equipment supplied.
3.7. The inner and outer surfaces of the elbow of the pulverized coal pipe should be smooth and clean, with thorns, burrs, fleshy or lack of meat, no cracks, looseness, pores or bubbles, and the painting should be uniform and consistent.
3.8. The elbow of the pulverized coal pipe has a smooth transition, a smooth and flat surface, and a height difference of 1mm.
3.9. No matter what method is used to make the elbow of pulverized coal pipe, the concentricity and overall quality of the elbow must be guaranteed.
3.10. The bending angle of the elbow of the pulverized coal pipe is accurate, and the angle deviation is 03°。The end face of the elbow and the end face of the straight pipe section are at right angles to the center line of the pipeline, and it is strictly forbidden to twist.
3.11. The elbow of pulverized coal pipe has good thermal stability to ensure long-term normal operation.
3.12. The elbow connection mode of pulverized coal pipe is welding (butting);Pipe and elbow material Q235A, design thickness 10 mm, ovality less than 05mm, all welds need to be tested for oil seepage, and the radiation sampling test is qualified.
3.13. The interface size and installation size of the elbow of the pulverized coal pipe should fully meet the installation size requirements of the design institute's drawings. The connection between the elbow and the pipeline adopts manual arc welding, and the bidder carries out welding process treatment on the welding surface of the pipeline, and lays the groove according to the requirements to meet the on-site manual arc welding welding. There are no special requirements for on-site welding of the product to ensure that the product has good welding performance when welding at room temperature on site. The butt weld of the elbow of the pulverized coal pipe ensures that there are no defects such as cracks, porosity, and scars. All pulverized coal pipe elbows have welded transition straight pipe sections at both ends, which should be completed in the manufacturing plant and delivered as a whole together with the pulverized coal pipe elbows. The length of the pipe section meets the requirements of the design drawings, and the inner wall of the ceramic sheet is smoothly transitioned from the part that is not pasted with the ceramic sheet, and the ceramic sheet forms a smooth surface as a whole.
3.After the processing of the metal shell of the elbow of the 14 pulverized coal pipe is completed, the inner wall of the elbow is thoroughly derusted and polished before the ceramic sheet is pasted.
3.15. The elbow of the pulverized coal pipe is lined with alumina ceramic sheet, and the thickness of the ceramic sheet is 80mm, the thickness deviation of the inner lining layer is 05mm。The pasted pipe fittings and the unpasted straight pipe should be connected and the transition should be good.