1. The joint surface with large cylinder deformation or serious steam leakage, using the method of grinding the joint surface
If the joint surface of the upper cylinder is deformed within the range of 0.05 mm, the joint surface of the upper cylinder is used as the reference surface, and red Dan or embossed blue paper is applied to the joint surface of the lower cylinder, and the lower cylinder is scraped according to the trace. If the deformation of the joint surface of the upper cylinder is large, apply red Dan in the upper cylinder, and develop the trace with a large flat ruler to level the upper cylinder. Or use the mechanical processing method to level the upper cylinder joint surface, and then use the above cylinder as the reference to scrape the lower cylinder joint surface. There are two ways to grind the cylinder joint surface:
(1) It is a bolt that does not close the joint surface. The jack is slightly pushed to move forward and backward with the jack, and the scraping is performed according to the coloring condition of the red joint of the lower cylinder joint surface. This method is suitable for a high-pressure cylinder with a strong structural rigidity.
(2) It is a bolt with tight joint surface. According to the tightness of the joint surface of the feeler gauge, the value and the trace of the extrusion are measured, and the joint surface is repaired. This method can eliminate the influence of the vertical arc of the cylinder on the gap.
2. Use appropriate cylinder sealing material
Because there is no uniform national standard and industry standard for steam turbine cylinder sealant, the raw materials and formulas are also different, and the product quality is uneven. When selecting the cylinder sealant of steam turbine, it is necessary to choose a reputation in the industry. Guaranteed regular manufacturers to ensure the tightness of the cylinder after maintenance.
3. Local repair welding method
Since the cylinder joint surface is washed or corroded by steam, the groove is added with a suitable electrode, and the trace is made with a flat plate or a flat ruler, and the weld bead and the joint surface are in the same plane. When the cylinder joint surface is deformed greatly or the steam leakage is serious, one or two 10-20mm wide dense clearance gap seals are repaired on the joint surface of the lower cylinder, and then measured with a flat ruler or a buckle cylinder, and painted with red Until the gap is eliminated. The process of this operation is also very simple, preheat the cylinder to 150 ° C before welding, and then perform partial reflow or jump welding at room temperature. Use austenitic electrodes, such as A407, A412, and use asbestos cloth to cover the insulation and slow cooling after welding. After the room temperature is cooled, the sanding is performed.
4. Coating or spraying of the cylinder joint surface
When the cylinder joint surface leaks in a large area and the gap is about 0.50 mm, in order to reduce the workload of the scraping, a coating process can be used. The cylinder is used as the anode, the coating is used as the cathode, and the electrolytic solution is repeatedly applied on the joint surface of the cylinder. The thickness of the coating depends on the gap of the cylinder joint surface. The type of the coating depends on the material of the cylinder and the shaving. Process depends. Spraying is the use of a dedicated high-temperature flame spray gun to heat the metal powder to a molten or plastic state and then spray it onto the treated cylinder surface to form a coating method with the desired properties. The utility model has the advantages that the equipment is simple, the operation is convenient and the coating is firm, and the cylinder temperature after spraying is only 70° C.-80° C., the cylinder is not deformed, and the heat-resistant, wear-resistant and corrosion-resistant coating can be obtained. It is noted that the cylinder surface should be ground, degreased and pulled before application and spraying. After the application and spraying, the coating should be ground to ensure the tight joint surface.