1. Maintenance methods and quality standards for IS series clean water centrifugal pumps, IR hot water pumps, IY single-stage oil pumps, IH chemical pumps and other series of single-stage single-suction centrifugal pumps.
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The pump body and base should be free of cracks, and the casting surface of the pump body scroll chamber and the inner wall of the liquid channel should be smooth. " to repair.
The flatness of the middle surface between the pump body and the pump cover of the double-suction impeller centrifugal pump shall not exceed 0.1mm when checked with a one-meter-long flat ruler, and a paper pad of 0.2~0.25mm shall be used during assembly.
2. The level of pump body installation
a. Single-suction centrifugal pump: longitudinal (along the direction of the pump axis) 0.05mm/m; transverse (perpendicular to the pump axis) 0.10mm/m.
b. Double suction centrifugal pump: 0.05m/m in both vertical and horizontal directions.
3. Single-stage centrifugal pump shaft and shaft sleeve
1) The pump shaft should not have defects such as corrosion and cracks. When repairing or replacing the pump shaft, non-destructive testing can be performed to detect whether there are cracks.
2) The surface roughness of the journal of the pump shaft: 3.2 where the impeller, bushing and coupling are installed, 1.6 where the rolling bearing is installed, and 0.8 where the sliding bearing is installed
3) Take the journals at the two bearings as the fulcrum, use a dial gauge to check the radial runout of the journals of the assembled impeller, shaft sleeve and coupling, which should not be greater than 0.03mm.
4) The offset from the center of the keyway to the centerline of the journal should not exceed 0.06mm, and the skew should not exceed 0.03mm/100mm.
5) After the keyway is worn, it can be appropriately increased according to the wear condition, but the maximum can only be increased by one level according to the standard size. When the structure and force allow, another keyway can be opened in the direction of 900 or 1200 of the original keyway.
6) After the journal is worn, it can be repaired by electroplating, spraying or coating.
7) The material of the shaft sleeve should conform to the drawing; the shaft sleeve is not allowed to have cracks, and the outer surface is not allowed to have casting defects such as sand holes, pores, and looseness.
8) Use H8/h8 or H9/h9 for the match between the bushing and the shaft.
4. Single-stage centrifugal pump impeller
1) The surface of the impeller of the centrifugal pump and the inner wall of the liquid flow channel should be cleaned, and there should be no sticky sand, burrs and dirt; the connection between the processing surface and the non-processing surface of the flow channel inlet should be smooth.
2) The impeller and the shaft are generally matched with H7/h6.
3) The newly installed centrifugal pump impeller must be statically balanced, and the unbalanced weight for static balance should not be greater than the value in Table 6; when it exceeds, the weight removal method should be used to cut from both sides of the impeller, and the thickness of the cut should not exceed the original wall thickness of the impeller 1/3 of the cutting part should be smoothly connected to the uncut part.