How to assemble a centrifugal pump?
Pump cleaning and inspection
1. The centrifugal pump of the whole factory is not suitable for disassembly during the anti-rust guarantee period, only the appearance is cleaned. Disassembly, cleaning and inspection shall be in accordance with the equipment technical documents when the anti-rust guarantee period or obvious defects are required to be disassembled. When there is no regulation, the following requirements shall be met: the impeller parts shall be cleaned and cleaned, and the impeller shall be free of damage; the cooling water pipeline shall be cleaned and cleaned, and shall be kept unobstructed; the pipeline pump and the coaxial pump shall not be disassembled.
2. The cleaning and inspection of the disassembled pump shall comply with the following requirements: the main parts, components and ancillary equipment of the centrifugal pump, the mid-section and the set parts, the end faces of the parts shall not be scratched or scratched, and the surface of the shaft shall not have cracks or pressure. Injury to other defects, moisture should be removed after cleaning and the parts, parts and equipment should be lubricated and placed in the order of assembly; the vertical split surface of the pump casing should not be disassembled and cleaned.
The longitudinal installation horizontal deviation of the pump installed as a whole
The deviation value should not be greater than 0.10/1000, the horizontal installation horizontal deviation should not be greater than 0.20/1000, and should be measured on the inlet and outlet flange faces of the pump or other horizontal surfaces. The horizontal and horizontal installation horizontal deviation of the disassembled pump should not exceed 0.05/1000, and should be measured in the horizontal mid-section, the exposed part of the shaft, and the horizontal processing surface of the base.
The correction of the centrifugal pump
1. When the drive shaft and the pump shaft, the drive shaft and the transmission shaft are connected by a coupling, the radial displacement, end clearance and axis inclination of the two coupling halves shall comply with the provisions of the equipment technical documents. When there is no regulation, it shall comply with the provisions of the General Specification for Construction and Acceptance of Mechanical Equipment Installation Engineering.
2. When the drive shaft and the pump shaft are connected by a belt, the parallelism of the two shafts and the offset of the two wheels shall comply with the relevant regulations.
3. When the steam turbine driven pump and the pump for conveying high temperature and low temperature liquid (boiler feed water pump, hot oil pump, cryopump, etc.) are calibrated under normal temperature conditions, the compensation value of temperature change shall be reserved according to the design regulations.
Installation of high speed pump or large disintegration pump
The radial and end face runout values of the main parts such as the rotor impeller, the bushing, the impeller seal ring, the balance disc, and the journal should be measured. The allowable deviation should be in accordance with the equipment and technical documents.
The radial total clearance between the rotor component and the housing component of the rotor component shall comply with the provisions of the equipment technical documents.
The axial direction of the impeller in the volute chamber and the rear axial clearance, the axial dimension of the segmental multistage pump shall comply with the provisions of the equipment technical documents; the thickness of the original gasket between the planes of the multistage pump shall not be changed. The axial clearance between the temperature balance disc (drum) and the balance sleeve shall be 0.04 to 0.08 mm for the single-shell segment type pump and 0.35 to 1 mm for the double-shell pump; the shaft between the thrust bearing and the thrust plate For the total gap, the single-shell segmented pump should be 0.5 to 1 mm, and the double-shell pump should be 0.5 to 0.7 mm. The centerline of the impeller outlet should be aligned with the pump casing flow centerline. The multistage pump is in balance. In the case where the disc is in close contact with the balance plate, the width of the impeller V1 should be within the width of the vane inlet.
Centrifugal pump bearing plain bearing The back of the bearing bush should be closely fitted with the bearing seat. The interference value should be in the range of 0.02~0.04mm; the top clearance and side clearance of the bearing bush and the journal should meet the requirements of the equipment technical documents.
The tolerance of the rolling bearing to the shaft and the bearing housing, the axial clearance between the rolling bearing and the end cover, the axial expansion gap caused by the medium temperature, the radial clearance of the radial thrust bearing and its preload force shall be in accordance with the equipment technical documents. The requirements are checked and adjusted. When there is no regulation, it shall be implemented in accordance with the provisions of the current national standards.
Assembly packing seal
The radial total clearance shall be in accordance with the equipment technical documentation. When there is no regulation, it should meet the requirements of Table 2-2. After the packing is pressed, the inlet and outlet of the packing ring should be aligned or the packing ring should be slightly outward.
The gaps and contact requirements of other sealed mechanical seals, floating ring seals, labyrinth seals and other forms of shaft seals shall comply with the provisions of the equipment technical documents.
When there is no regulation, it should meet the requirements of industry standards.
The axial yaw of the rotor The shaft rotor should be flexible after assembly. The axial yaw of the rotor should meet the requirements of the equipment technical documents.
Assembly of the pump casing The inner casing and outer casing of the double-shell pump should be centered according to the technical documents of the equipment when assembling. The amount of tension of the stud tightening and the angle of rotation of the nut should meet the design requirements.
Inspection of the centrifugal pump before commissioning
1. The steering of the drive should match the steering of the centrifugal pump.
2. The steering of the pipeline pump and the coaxial pump should be ascertained.
3. The steering of the shielded pump should be checked.
4. There should be no looseness at each fixed connection.
5. The specifications and quantity of the lubricant added to each lubrication part shall comply with the provisions of the technical documents of the equipment. The parts with pre-lubrication requirements shall be pre-lubricated according to the regulations.