Handling Method Of Cylinder

1. The joint surface of the cylinder with large deformation or serious steam leakage adopts the method of grinding and scraping the joint surface

If the upper cylinder joint surface is deformed within the range of 0.05mm, the upper cylinder joint surface is the reference surface, and the lower cylinder joint surface is coated with red dan or embossed blue paper, and the lower cylinder is scraped according to the traces. If the joint surface of the upper cylinder has a large amount of deformation, paint red pills on the upper cylinder, use a large flat ruler to develop traces, and grind the upper cylinder flat. Or take the method of machining to level the upper cylinder joint surface, and then scrape the lower cylinder joint surface as the benchmark. There are generally two methods for scraping the joint surface of the cylinder:

(1) The bolt that is not tightly bonded with the surface, use a jack to slightly push the upper cylinder back and forth to move, and study and scrape according to the coloring of the red dan of the lower cylinder bonding surface. This method is suitable for high-pressure cylinders with strong structural rigidity.

(2) It is a bolt of the tight joint surface, according to the tightness of the joint surface of the feeler gauge, the value and the traces of extrusion are measured, and the joint surface is scraped, this method can eliminate the influence of the cylinder vertical arc on the clearance.

2. Adopt appropriate cylinder sealing materials

The quality of steam turbine cylinder sealant products is uneven; When choosing a turbine cylinder sealant, it is necessary to choose a regular manufacturer with a reputation in the industry and guaranteed product quality to ensure the tightness of the cylinder after overhaul treatment.

3. The method of local repair welding

Since the cylinder joint surface is washed by steam or corroded to produce grooves, the appropriate welding rod is selected to add the grooves, and the traces are developed with a flat plate or flat ruler, and the scraping weld bead and the bonding surface are in the same plane. When the cylinder joint surface is deformed or the steam leakage is serious, one or two 10-20mm wide dense elimination gap sealing tapes are welded on the joint surface of the lower cylinder, and then measured with a flat ruler or buckled cylinder, and coated with red dan scraping until the gap is eliminated. The process of this operation is also very simple, preheating the cylinder to 150°C before welding, and then performing staged unwelding or skip welding at room temperature. Choose austenitic electrodes, such as A407 and A412, and cover with asbestos cloth after welding to keep warm and cool slowly. Allow to cool down at room temperature and then polish and scrape.

4. Coating or spraying of cylinder joint surface

When the cylinder joint surface leaks steam in a large area and the gap is about 0.50mm, in order to reduce the workload of scraping, the coating process can be used. Use the cylinder as the anode, the coating as the cathode, and repeatedly apply the electrolytic solution on the joint surface of the cylinder, the thickness of the coating should be determined according to the size of the gap between the cylinder joint surface, and the type of coating should be determined according to the material of the cylinder and the scraping process. Spraying is a special high-temperature flame spray gun to heat the metal powder to melt or reach a plastic state and then spray it on the surface of the treated cylinder to form a coating method with the required properties. Its characteristics are simple equipment, easy to operate, solid coating, cylinder temperature after spraying is only 70 °C ~ 80 °C will not deform the cylinder, and can obtain heat-resistant, wear-resistant, anti-corrosion coating. It should be noted that the cylinder surface should be polished, degreased and brushed before coating and spraying, and the coating should be scraped after coating and spraying to ensure the tightness of the bonding surface.

5. The method of combining the surface padding

If the local gap leakage of the joint surface is not very large, 80~100 purpose copper mesh can be used to reduce its hardness by heat treatment, and then cut into an appropriate shape, spread on the steam leakage of the joint surface, and then equipped with cylinder sealant. If the gap of the joint surface is large and the leakage is serious, a groove with a width of 50mm and a depth of 5mm can be opened on the upper and lower joint surfaces, and the toothed pad of IGr18Ni9Ti is embedded in the middle, and the thickness of the toothed pad is generally about 0.05~0.08mm larger than the depth of the groove, and can be adjusted by stainless steel gaskets of the same shape.