Repair and Assembling of Main Parts of D - type Centrifugal Water
The following to D-type multi-stage centrifugal pump, for example, describes its repair and assembly methods.
(A) D-type centrifugal pump disassembly and precautions
Pump disassembly is an important maintenance process. Before disassembly, the structure of the pump and the connection should be a bit
Solution, in order to facilitate the smooth demolition work.
1. Removal of water pump
(1) with a pipe clamp remove the water pipe, balance the water pipe and water injection funnel.
(2) Remove the coupling with the ejector.
(3) Using a wrench, unscrew the nut on the gland of the water side bearing, remove the bolt, and remove the outer bearing gland.
(4) unscrew the water section, stuffing box body, the connection between the bearing nut, with the top wire to fill the body and the bearing body
Separate, remove the bearing body.
(5) Unscrew the nut on the shaft, and then remove the bearing, bearing inner gland, retaining ring.
(6) Remove the packing gland, with a hook hook out of the packing room in the packing and water seal ring, with the top wire to fill the box with the body
Water segment separation, remove the packing material body.
(7) in turn to remove the axis of the sleeve and keys, with screws through the screw hole to the top out of the balance plate, remove the key.
(8) Unscrew the nuts on the front bearing gland, remove the bolts, and remove the outer gland and sleeve. Unscrew the inlet section
Remove the front bearing assembly by attaching the bolts to the bearing body. Remove the bearing in turn, bearing inner gland, retaining ring and sleeve.
(9) Remove the packing gland, remove the packing and water seal ring.
(10) Use a large wrench to unscrew the four nuts that tighten the bolts connecting the inlet, middle and outlet sections and remove the bolts.
(11) with a flat shovel or a special steel wedge into the drainage section and the middle section of the joint symmetry pry loose, remove the water segment components.
(12) with a small crowbar pry out the water wheel, pay attention to force and symmetry as close to the water wheel, to prevent the bad water wheel,
And remove the axis keys.
(13) with a flat shovel inserted in the middle and middle of the connection between the slit, loose and remove the middle.
(14), the removal of the water wheel and key is carried out as described above until the first stage water wheel is removed.
(15) Pull the shaft out of the outlet section.
2. Disassembly should pay attention to matters
(1) Before dismantling the pump body, water inlet section, middle section and drainage section, the original assembly position of each section should be numbered so that
In the order of maintenance after assembly. Number can be used to fight steel stamp or use paint and lead oil to write marks and other methods.
(2) down on the various parts and a variety of bolts, etc., should be classified custody to prevent loss.
(3) attention should be paid to the demolition of the screw shaft rotation.
(4) the middle of the water pump without bracket, after the removal of several middle, the wedge wedge on both sides of the wedge to prevent the pump shaft due to
In a cantilever state and produce bending phenomenon. Remove the pump shaft should be hung up, or placed on a flat steel plate to prevent
bending.
(5) on the serious wear and tear parts or demolition of the damaged parts, shall not be arbitrarily lost in preparation for purchase or mapping reference
Test use.
(6) for some serious corrosion, easy to open the connection, it should be scraped scale and corrosion and other objects, and with kerosene
Cleaning, the appropriate contact with lubricating parts, and then wooden hammer, plumb bob or hammer gently knock to remove, if necessary, can be demolished
open. Must be noted that must not blindly with the hammer to play, this will damage the parts.
(7) after the demolition of the pump should be promptly cleaned. Cleaning the shell surface adhesion of grease and rust; scrape off the water wheel
Inner and outer surface and sealing ring, guide sets, etc. accumulated at the scale and rust; clean water pipe and balance the water pipe and check whether the pipe is smooth; with kerosene cleaning pad, with gasoline cleaning roller bearings. If it is not assembled immediately, the cleaned part shall be coated with protective oil or grease on its joint surface.
(2) D-type centrifugal pump main parts inspection and repair
After the disintegration of the pump, the parts should be cleaned, inspected and classified. The parts are divided into usable parts, to be repaired pieces of waste 3 categories, organizations repair the parts to be repaired, the spare parts of the scrap pieces should be timely mapping, re-preparation of new pieces
(And make spare parts).
1. Repair of pump body
Pump damage is often due to mechanical stress or thermal stress caused by the role, sometimes due to handling collision, improper installation, low temperature cracking, overpressure, and high temperature effects may also be damaged. If the damage is serious, replace the new pump body; if the damage is less severe, can be used for repair.
Check the pump cracks, the first hand hammer gently hammer the pump body, such as hoarse sound, it shows that cracks, should be carefully looking for. The method of empirical inspection is to wipe the surface of the suspected cracked parts with kerosene, with a chalk smear surface, there will be cracks at a clear dip line.
To prevent crack propagation, a 3 mm diameter circular hole can be drilled at each end of the crack to eliminate local stress concentration where it is not subject to compression or sealing (eg on the flange joint surface).
Weld requirements are not very strict, little pressure position (such as base), can be cold welding repair; the greater the force or the need to seal the location, can be hot welding repair. If the pump body is found inside the deep groove or large holes, can be used epoxy resin mortar repair, welding can also be carried out. Leakage.
2. Repair of pump shafts
(1) When the water pump shaft cracks, the surface of serious corrosion and damage, journal wear groove marks, the shaft surface is washed out of the groove, roundness and cylindrical degree exceeds the provisions, and sufficient to affect the mechanical strength, should replace the new shaft .
(2) Straightness of the shaft should be straightened or replaced if it exceeds 1/3 of the inner diameter of the seal ring and 1/3 of the diameter of the water wheel.
(3) journal or filler part of the wear and tear can be used if the axle to repair, the turning amount shall not exceed 5% of the design diameter. Can also be used electroplating, metal spraying or inlay method for repair.
3. Repair of keyways
When the keyway is damaged badly, the new shaft should be replaced. If the damage is not serious, it can be dealt with by widening the original key way, allowing to widen the original keyway width by 5% and with the new key. For the transmission power of the shaft can be smaller to open a new slot. The centerline of a keyway and its axis
The parallelism is not more than 0.3% 0, the offset is not more than 0.6mm.
4. Repair of bearings
Pump bearing repair can refer to the method described in Chapter IV.
5. Repair of water wheel
Water wheel in case of one of the following circumstances, the repair difficulties, should replace the new water wheel: the surface of serious cracks; surface formation of more trachoma, cavitation Ma hole or wear larvae L; due to erosion leaving the water wheel thinner, Strength; water wheel blades were foreign body break; water wheel at the entrance of the more serious phenomenon of partial grinding.
Water wheels commonly used repair methods are repair welding, epoxy mortar repair. Water wheel should be handled before welding clean, and then the entire water wheel evenly heated. According to the material of the water wheel, different welding methods can be used: stainless steel water wheel of high-pressure pump, stainless steel gas welding; low-pressure cast iron water wheel, with brazing or cast iron repair welding; Wear a serious water wheel, epoxy mortar can be used to repair, wear the entire blade is coated with a layer of epoxy resin sand
Pulp, can receive better results.
The new water changing wheel should meet the following requirements:
(1) The concentricity of the shaft axis of the water wheel shaft and the axis of the outer circle at the water inlet of the water wheel shall not be greater than that specified in Table 6-4.
Table 6-4 Tolerance of water wheel three position mm
Water wheel shaft hole diameter <18> 18 ~ 30> 30 ~ 50> 50 ~ 120> 120 a 260
Tolerance of three-dimensional position 0.020 0.025 O. 030 0.040 O. 050
(2) the water wheel at the front and rear side of the surface roughness is not greater than O. 8 ¨ m, the axis of the hole and the installation of the mouth of the surface roughness
Not more than O. Mu] m.
(3) water runner should be smooth and smooth, leaving no burr.
(4) the new system of water wheel must be static balance test. If the cutting side of the board to find a balance, cutting depth shall not exceed the thickness of the side plate l / 3, the cutting part should be smooth with the original surface. The maximum unbalance mass of the water wheel shall not exceed the requirements in Table 6-5.
Table 6-5 Water wheel static balance tolerance
Outer diameter of water wheel / mm <200> 200 to 300> 300 to 400> 400 to 500> 500 to 700> 700 to 900
Static balance tolerance / g 3 5 8 10 15 20
6. Repair of balance disc and balance ring
Balance disc and balance ring damage is mainly between the two contact surface wear. _ If the wear and tear uneven and grooved, can be used for grinding or grinding flat repair; serious wear and tear, need to replace the balance plate or balance ring. The new balance plate sealing surface should be perpendicular to the axis, the verticality of not more than 0.3 ‰, the surface roughness of not more than 1.6μm. Balance disk and friction ring, balance ring and the water section should be fitted closely, the contact area of 70% or more.
7. Repair of guide
The guide shall not be cracked, the depth of erosion shall not exceed 4mm, and the length of the blade tip shall be eroded not more than 6mm. If the wear size within the specified range, do a new tip with brass welding or bonding, or need to replace the director.
8. Generally do not repair only replacement parts
Repair only repair parts are not only the seal ring (large El ring), guide sets (small mouth ring), water wheel block sets (interval sleeve), bushings, balance sets (string of water), seals . The clearance between the inside diameter of the seal ring and the outside diameter of the water inlet and the clearance between the sleeve and the guide sleeve shall not exceed the requirements specified in Table 6-6.
Table 6-6 Seal ring, guide sleeve with the gap mm
Seal ring, guide sleeve inner diameter radius gap maximum wear radius gap
80 a 120 O. 15 to O. 22 0.44
> 120-150 0.175-0.255 O. 51
> 150_180 O. 20-0.28 O. 56
> 180 to 220 0.225 to 0.3, 15 0.63
> 220 a 260 O. 25-O. 34 0.68
> 260-290 O. 25 to 0.35 0.70
> 290 to 320 0.275-0.375 O. 75
> 320 to 360 O. 30 a 0.40 O. 80
The following to D-type multi-stage centrifugal pump, for example, describes its repair and assembly methods.
(A) D-type centrifugal pump disassembly and precautions
Pump disassembly is an important maintenance process. Before disassembly, the structure of the pump and the connection should be a bit
Solution, in order to facilitate the smooth demolition work.
1. Removal of water pump
(1) with a pipe clamp remove the water pipe, balance the water pipe and water injection funnel.
(2) Remove the coupling with the ejector.
(3) Using a wrench, unscrew the nut on the gland of the water side bearing, remove the bolt, and remove the outer bearing gland.
(4) unscrew the water section, stuffing box body, the connection between the bearing nut, with the top wire to fill the body and the bearing body
Separate, remove the bearing body.
(5) Unscrew the nut on the shaft, and then remove the bearing, bearing inner gland, retaining ring.
(6) Remove the packing gland, with a hook hook out of the packing room in the packing and water seal ring, with the top wire to fill the box with the body
Water segment separation, remove the packing material body.
(7) in turn to remove the axis of the sleeve and keys, with screws through the screw hole to the top out of the balance plate, remove the key.
(8) Unscrew the nuts on the front bearing gland, remove the bolts, and remove the outer gland and sleeve. Unscrew the inlet section
Remove the front bearing assembly by attaching the bolts to the bearing body. Remove the bearing in turn, bearing inner gland, retaining ring and sleeve.
(9) Remove the packing gland, remove the packing and water seal ring.
(10) Use a large wrench to unscrew the four nuts that tighten the bolts connecting the inlet, middle and outlet sections and remove the bolts.
(11) with a flat shovel or a special steel wedge into the drainage section and the middle section of the joint symmetry pry loose, remove the water segment components.
(12) with a small crowbar pry out the water wheel, pay attention to force and symmetry as close to the water wheel, to prevent the bad water wheel,
And remove the axis keys.
(13) with a flat shovel inserted in the middle and middle of the connection between the slit, loose and remove the middle.
(14), the removal of the water wheel and key is carried out as described above until the first stage water wheel is removed.
(15) Pull the shaft out of the outlet section.
2. Disassembly should pay attention to matters
(1) Before dismantling the pump body, water inlet section, middle section and drainage section, the original assembly position of each section should be numbered so that
In the order of maintenance after assembly. Number can be used to fight steel stamp or use paint and lead oil to write marks and other methods.
(2) down on the various parts and a variety of bolts, etc., should be classified custody to prevent loss.
(3) attention should be paid to the demolition of the screw shaft rotation.
(4) the middle of the water pump without bracket, after the removal of several middle, the wedge wedge on both sides of the wedge to prevent the pump shaft due to
In a cantilever state and produce bending phenomenon. Remove the pump shaft should be hung up, or placed on a flat steel plate to prevent
bending.
(5) on the serious wear and tear parts or demolition of the damaged parts, shall not be arbitrarily lost in preparation for purchase or mapping reference
Test use.
(6) for some serious corrosion, easy to open the connection, it should be scraped scale and corrosion and other objects, and with kerosene
Cleaning, the appropriate contact with lubricating parts, and then wooden hammer, plumb bob or hammer gently knock to remove, if necessary, can be demolished
open. Must be noted that must not blindly with the hammer to play, this will damage the parts.
(7) after the demolition of the pump should be promptly cleaned. Cleaning the shell surface adhesion of grease and rust; scrape off the water wheel
Inner and outer surface and sealing ring, guide sets, etc. accumulated at the scale and rust; clean water pipe and balance the water pipe and check whether the pipe is smooth; with kerosene cleaning pad, with gasoline cleaning roller bearings. If it is not assembled immediately, the cleaned part shall be coated with protective oil or grease on its joint surface.
(2) D-type centrifugal pump main parts inspection and repair
After the disintegration of the pump, the parts should be cleaned, inspected and classified. The parts are divided into usable parts, to be repaired pieces of waste 3 categories, organizations repair the parts to be repaired, the spare parts of the scrap pieces should be timely mapping, re-preparation of new pieces
(And make spare parts).
1. Repair of pump body
Pump damage is often due to mechanical stress or thermal stress caused by the role, sometimes due to handling collision, improper installation, low temperature cracking, overpressure, and high temperature effects may also be damaged. If the damage is serious, replace the new pump body; if the damage is less severe, can be used for repair.
Check the pump cracks, the first hand hammer gently hammer the pump body, such as hoarse sound, it shows that cracks, should be carefully looking for. The method of empirical inspection is to wipe the surface of the suspected cracked parts with kerosene, with a chalk smear surface, there will be cracks at a clear dip line.
To prevent crack propagation, a 3 mm diameter circular hole can be drilled at each end of the crack to eliminate local stress concentration where it is not subject to compression or sealing (eg on the flange joint surface).
Weld requirements are not very strict, little pressure position (such as base), can be cold welding repair; the greater the force or the need to seal the location, can be hot welding repair. If the pump body is found inside the deep groove or large holes, can be used epoxy resin mortar repair, welding can also be carried out. Leakage.
2. Repair of pump shafts
(1) When the water pump shaft cracks, the surface of serious corrosion and damage, journal wear groove marks, the shaft surface is washed out of the groove, roundness and cylindrical degree exceeds the provisions, and sufficient to affect the mechanical strength, should replace the new shaft .
(2) Straightness of the shaft should be straightened or replaced if it exceeds 1/3 of the inner diameter of the seal ring and 1/3 of the diameter of the water wheel.
(3) journal or filler part of the wear and tear can be used if the axle to repair, the turning amount shall not exceed 5% of the design diameter. Can also be used electroplating, metal spraying or inlay method for repair.
3. Repair of keyways
When the keyway is damaged badly, the new shaft should be replaced. If the damage is not serious, it can be dealt with by widening the original key way, allowing to widen the original keyway width by 5% and with the new key. For the transmission power of the shaft can be smaller to open a new slot. The centerline of a keyway and its axis
The parallelism is not more than 0.3% 0, the offset is not more than 0.6mm.
4. Repair of bearings
Pump bearing repair can refer to the method described in Chapter IV.
5. Repair of water wheel
Water wheel in case of one of the following circumstances, the repair difficulties, should replace the new water wheel: the surface of serious cracks; surface formation of more trachoma, cavitation Ma hole or wear larvae L; due to erosion leaving the water wheel thinner, Strength; water wheel blades were foreign body break; water wheel at the entrance of the more serious phenomenon of partial grinding.
Water wheels commonly used repair methods are repair welding, epoxy mortar repair. Water wheel should be handled before welding clean, and then the entire water wheel evenly heated. According to the material of the water wheel, different welding methods can be used: stainless steel water wheel of high-pressure pump, stainless steel gas welding; low-pressure cast iron water wheel, with brazing or cast iron repair welding; Wear a serious water wheel, epoxy mortar can be used to repair, wear the entire blade is coated with a layer of epoxy resin sand
Pulp, can receive better results.
The new water changing wheel should meet the following requirements:
(1) The concentricity of the shaft axis of the water wheel shaft and the axis of the outer circle at the water inlet of the water wheel shall not be greater than that specified in Table 6-4.
Table 6-4 Tolerance of water wheel three position mm
Water wheel shaft hole diameter <18> 18 ~ 30> 30 ~ 50> 50 ~ 120> 120 a 260
Tolerance of three-dimensional position 0.020 0.025 O. 030 0.040 O. 050
(2) the water wheel at the front and rear side of the surface roughness is not greater than O. 8 ¨ m, the axis of the hole and the installation of the mouth of the surface roughness
Not more than O. Mu] m.
(3) water runner should be smooth and smooth, leaving no burr.
(4) the new system of water wheel must be static balance test. If the cutting side of the board to find a balance, cutting depth shall not exceed the thickness of the side plate l / 3, the cutting part should be smooth with the original surface. The maximum unbalance mass of the water wheel shall not exceed the requirements in Table 6-5.
Table 6-5 Water wheel static balance tolerance
Outer diameter of water wheel / mm <200> 200 to 300> 300 to 400> 400 to 500> 500 to 700> 700 to 900
Static balance tolerance / g 3 5 8 10 15 20
6. Repair of balance disc and balance ring
Balance disc and balance ring damage is mainly between the two contact surface wear. _ If the wear and tear uneven and grooved, can be used for grinding or grinding flat repair; serious wear and tear, need to replace the balance plate or balance ring. The new balance plate sealing surface should be perpendicular to the axis, the verticality of not more than 0.3 ‰, the surface roughness of not more than 1.6μm. Balance disk and friction ring, balance ring and the water section should be fitted closely, the contact area of 70% or more.
7. Repair of guide
The guide shall not be cracked, the depth of erosion shall not exceed 4mm, and the length of the blade tip shall be eroded not more than 6mm. If the wear size within the specified range, do a new tip with brass welding or bonding, or need to replace the director.
8. Generally do not repair only replacement parts
Repair only repair parts are not only the seal ring (large El ring), guide sets (small mouth ring), water wheel block sets (interval sleeve), bushings, balance sets (string of water), seals . The clearance between the inside diameter of the seal ring and the outside diameter of the water inlet and the clearance between the sleeve and the guide sleeve shall not exceed the requirements specified in Table 6-6.
Table 6-6 Seal ring, guide sleeve with the gap mm
Seal ring, guide sleeve inner diameter radius gap maximum wear radius gap
80 a 120 O. 15 to O. 22 0.44
> 120-150 0.175-0.255 O. 51
> 150_180 O. 20-0.28 O. 56
> 180 to 220 0.225 to 0.3, 15 0.63
> 220 a 260 O. 25-O. 34 0.68
> 260-290 O. 25 to 0.35 0.70
> 290 to 320 0.275-0.375 O. 75
> 320 to 360 O. 30 a 0.40 O. 80
Manufacturers recommend: Shenlong stainless steel submersible pump
Keywords:D-type centrifugal pumps, repair and assembly
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