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Maintenance methods of centrifugal pump components
Source:未知|Popularity:0|release date:2020-11-27 15:43:04
Maintenance methods of centrifugal pump components
Packing seal maintenance method
1. clean the packing box of centrifugal pump, and check whether there are scratches and burrs on the surface of the shaft. The packing box should be cleaned and the shaft surface should be smooth.
2. Check the shaft runout. The unbalance of the rotor runout should be within the allowable range, so as to avoid excessive vibration and adverse to the packing.
3. Apply sealant or lubricant suitable for medium on packing box and shaft surface.
4. For the packing packed in rolls, take a wooden stick with the same size as the journal, wind the packing on it, and then cut it with a knife. The knife edge should be 45 ° inclined.
5. The fillers should be filled one by one, not several at a time. The method is to take a piece of packing, apply lubricant, hold one end of the packing interface in both hands, pull it out along the axial direction, make it spiral, and then put it into the journal through the incision. Do not pull apart along the radial direction to avoid uneven interface.
6. Take a metal shaft sleeve of the same size material or lower hardness than the shaft of the packing box, push the packing into the deep part of the box, and apply certain pressure to the shaft sleeve with the gland to make the packing get pre compression. The preloading shrinkage is 5% ~ 10%, and the maximum is 20%. Turn the shaft for another circle and take out the shaft sleeve.
7. In the same way, load the second and third. Note: when the number of fillers is 4-8, the interfaces should be staggered by 90 degrees; two fillers should be staggered by 180 degrees; 3-6 pieces should be staggered by 120 degrees to prevent leakage through the interface.
8. After the last packing is filled, the gland should be used for compaction, but the pressing force should not be too large. At the same time, rotate the shaft by hand to make the assembly pressing force tend to parabola distribution. Then loosen the cover slightly.
9. Carry out operation test. If it can't be sealed, compress some packing; if the heating is too large, loosen it. It can be put into use only when the temperature of the packing is 30-40 ℃ higher than that of the environment. Centrifugal pump packing seal assembly technical requirements, the installation of packing seals, should comply with the provisions of technical documents.
If not specified, the following requirements shall be met:
1. Check the radial runout of the shaft at the sealing parts, and the allowable radial runout of the shaft is in the range of 0.03 ~ 0.08mm;
2. The diameter clearance between the liquid seal ring and the shaft sleeve is generally 1.00 ~ 1.50mm, and the diameter clearance between the liquid seal ring and the packing box is generally 0.15 ~ 0.20mm;
3. The diameter clearance between the packing gland and the shaft sleeve is generally 0.75 ~ 1.00mm, and the surrounding clearance should be uniform; 4. The diameter clearance between the packing gland and the packing box is generally 0.10 ~ 0.30mm;
4. When there is a bottom ring of packing, the diameter clearance between the bottom ring and the shaft sleeve is generally 0.70 ~ 1.00mm;
5. After the packing is compressed, the liquid inlet hole of the liquid seal ring should be aligned with the liquid seal pipe, or the liquid seal ring slightly deviates to the outside;
6. For the packing packed in rolls, take a wooden stick with the same size as the shaft, wind the packing on it, and then cut it with a knife. The incision should be 45 ° inclined.
2. The technical standards for coupling maintenance include rigid coupling, gear coupling and elastic coupling
3. Rigid coupling rigid coupling is generally used on centrifugal pumps with low power. When overhauling, first remove the connecting bolt and rubber elastic ring. For the liquid with low temperature, the plane clearance between the two half couplings is 2.2 ~ 4.2mm, and when the temperature is high, it should be 1.55 ~ 2.05mm larger than the shaft displacement. The diameter of rubber elastic ring of coupling should be 0.15 ~ 0.35mm smaller than that of perforation. At the same time, special tools must be used to keep smooth and clean, and no bruises and scratches are allowed.
4. The gear coupling has good flexibility and automatic centering performance. The following methods are generally used for maintenance:
1. Check the meshing condition of the coupling tooth surface. The contact area along the tooth height is not less than 50%, along the tooth width is not less than 70%. There is no serious pitting, wear and crack on the tooth surface.
2. The full circle runout of the coupling outer gear ring is not more than 0.03mm, and the end face circular runout is not more than 0.02mm.
3. If it is necessary to remove the gear ring, special tools must be used instead of knocking to avoid bending or damage to the shaft. When reassembling, the ring gear should be heated to about 200 ℃ and then installed on the shaft. The interference between the outer gear ring and the shaft is generally 0.01 ~ 0.03mm.
4. When installing the intermediate cylinder or other parts, it should be assembled according to the original marks and data.
5. Tighten the bolts evenly with a torque wrench.
Diaphragm type elastic coupling
1. Clean and check the surface of the two half couplings, which should be free of cracks and wear. The surface matching with the intermediate spacer sleeve should be smooth and without burr. The coaxiality deviation of the two half couplings should be less than 0.003mm.
2. Clean and check the spring leaf to ensure there is no crack and deformation.
3. Clean and check the bolt, and the surface shall be free of crack, wear and deformation.
4.Alignment requirements: axial ± 0.03mm, radial ± 0.05mm.
Packing seal maintenance method
1. clean the packing box of centrifugal pump, and check whether there are scratches and burrs on the surface of the shaft. The packing box should be cleaned and the shaft surface should be smooth.
2. Check the shaft runout. The unbalance of the rotor runout should be within the allowable range, so as to avoid excessive vibration and adverse to the packing.
3. Apply sealant or lubricant suitable for medium on packing box and shaft surface.
4. For the packing packed in rolls, take a wooden stick with the same size as the journal, wind the packing on it, and then cut it with a knife. The knife edge should be 45 ° inclined.
5. The fillers should be filled one by one, not several at a time. The method is to take a piece of packing, apply lubricant, hold one end of the packing interface in both hands, pull it out along the axial direction, make it spiral, and then put it into the journal through the incision. Do not pull apart along the radial direction to avoid uneven interface.
6. Take a metal shaft sleeve of the same size material or lower hardness than the shaft of the packing box, push the packing into the deep part of the box, and apply certain pressure to the shaft sleeve with the gland to make the packing get pre compression. The preloading shrinkage is 5% ~ 10%, and the maximum is 20%. Turn the shaft for another circle and take out the shaft sleeve.
7. In the same way, load the second and third. Note: when the number of fillers is 4-8, the interfaces should be staggered by 90 degrees; two fillers should be staggered by 180 degrees; 3-6 pieces should be staggered by 120 degrees to prevent leakage through the interface.
8. After the last packing is filled, the gland should be used for compaction, but the pressing force should not be too large. At the same time, rotate the shaft by hand to make the assembly pressing force tend to parabola distribution. Then loosen the cover slightly.
9. Carry out operation test. If it can't be sealed, compress some packing; if the heating is too large, loosen it. It can be put into use only when the temperature of the packing is 30-40 ℃ higher than that of the environment. Centrifugal pump packing seal assembly technical requirements, the installation of packing seals, should comply with the provisions of technical documents.
If not specified, the following requirements shall be met:
1. Check the radial runout of the shaft at the sealing parts, and the allowable radial runout of the shaft is in the range of 0.03 ~ 0.08mm;
2. The diameter clearance between the liquid seal ring and the shaft sleeve is generally 1.00 ~ 1.50mm, and the diameter clearance between the liquid seal ring and the packing box is generally 0.15 ~ 0.20mm;
3. The diameter clearance between the packing gland and the shaft sleeve is generally 0.75 ~ 1.00mm, and the surrounding clearance should be uniform; 4. The diameter clearance between the packing gland and the packing box is generally 0.10 ~ 0.30mm;
4. When there is a bottom ring of packing, the diameter clearance between the bottom ring and the shaft sleeve is generally 0.70 ~ 1.00mm;
5. After the packing is compressed, the liquid inlet hole of the liquid seal ring should be aligned with the liquid seal pipe, or the liquid seal ring slightly deviates to the outside;
6. For the packing packed in rolls, take a wooden stick with the same size as the shaft, wind the packing on it, and then cut it with a knife. The incision should be 45 ° inclined.
2. The technical standards for coupling maintenance include rigid coupling, gear coupling and elastic coupling
3. Rigid coupling rigid coupling is generally used on centrifugal pumps with low power. When overhauling, first remove the connecting bolt and rubber elastic ring. For the liquid with low temperature, the plane clearance between the two half couplings is 2.2 ~ 4.2mm, and when the temperature is high, it should be 1.55 ~ 2.05mm larger than the shaft displacement. The diameter of rubber elastic ring of coupling should be 0.15 ~ 0.35mm smaller than that of perforation. At the same time, special tools must be used to keep smooth and clean, and no bruises and scratches are allowed.
4. The gear coupling has good flexibility and automatic centering performance. The following methods are generally used for maintenance:
1. Check the meshing condition of the coupling tooth surface. The contact area along the tooth height is not less than 50%, along the tooth width is not less than 70%. There is no serious pitting, wear and crack on the tooth surface.
2. The full circle runout of the coupling outer gear ring is not more than 0.03mm, and the end face circular runout is not more than 0.02mm.
3. If it is necessary to remove the gear ring, special tools must be used instead of knocking to avoid bending or damage to the shaft. When reassembling, the ring gear should be heated to about 200 ℃ and then installed on the shaft. The interference between the outer gear ring and the shaft is generally 0.01 ~ 0.03mm.
4. When installing the intermediate cylinder or other parts, it should be assembled according to the original marks and data.
5. Tighten the bolts evenly with a torque wrench.
Diaphragm type elastic coupling
1. Clean and check the surface of the two half couplings, which should be free of cracks and wear. The surface matching with the intermediate spacer sleeve should be smooth and without burr. The coaxiality deviation of the two half couplings should be less than 0.003mm.
2. Clean and check the spring leaf to ensure there is no crack and deformation.
3. Clean and check the bolt, and the surface shall be free of crack, wear and deformation.
4.Alignment requirements: axial ± 0.03mm, radial ± 0.05mm.