D-type horizontal multi-stage pump is a wide range of general-purpose mechanical equipment, which is used to transport clear water without solid particles and abrasives, without suspended matter, or other liquids with physical and chemical properties similar to clear water. The temperature of the liquid being transported is between -20°C and 80°C. It is widely used in various sectors of petroleum, chemical industry, electric power metallurgy, mining, shipbuilding, light industry, agriculture, civil and national defense, and occupies an important position in the national economy.
Assembly of D-type horizontal multi-stage pump
The assembly sequence of horizontal multistage pumps is generally opposite to the disassembly sequence. The quality of the assembly directly affects the normal operation of the pump, and affects the service life and performance parameters of the pump. Pay attention to the following points when assembling:
(1) The concentricity of the combined parts of the fixed part is guaranteed by the manufacturing accuracy and assembly quality of the parts. The machining accuracy and surface roughness of the parts should be protected, and no bumps, scratches, etc. are allowed to be used as a seal for sealing. The parts should be clean, and the tightening screws and bolts should be evenly stressed.
(2) The neutrality of the outlet channel of the impeller and the inlet channel of the guide vane is guaranteed according to the axial size of each part. The neutrality of the channel directly affects the performance of the pump, so the size of the pump cannot be adjusted at will.
(3) After the pump is assembled, before the packing is installed, turn the pump rotor by hand to check whether the rotor rotates flexibly in the pump and whether the axial displacement meets the specified requirements;
(4) After the above inspection meets the requirements, add packing at the shaft seals at both ends of the pump. Pay attention to the relative position of the packing ring in the packing chamber.
Disassembly of D-type horizontal multi-stage pump
The disassembly should be carried out in the reverse order of the assembly, and the manufacturing accuracy of the parts should be strictly protected from damage during disassembly. When disassembling the through rod, each middle section should be cushioned first to prevent the middle section from loosening and then sinking and bending the shaft.
1. Matters needing attention when disassembling D-type horizontal multi-stage pump
(1) Stop in the order of parking;
(2) The liquid (including cooling water) in the pump casing should be drained; when the bearing parts are lubricated with thin oil, the lubricating oil should be drained;
(3) Remove the auxiliary pipelines that hinder the disassembly, such as balance pipes, water seal pipes and other pipelines and leads;
(4) Disassembly should strictly protect the manufacturing accuracy of parts from damage. Colleagues who disassemble the tie rods should pad up each middle section with spacers to prevent the middle section from loosening and sinking and bending of the shaft.
2. Disassembly sequence of D-type horizontal multi-stage pump
(1) After removing the coupling, unscrew the bolts on the bearing end cover of the discharge side and the connecting bolts between the outlet section, the tail cover and the bearing body, and remove the bearing parts such as the bearing end cover and the bearing body;
(2) After unscrewing the round nut on the shaft and removing the bearing inner ring, bearing gland and retaining ring accordingly, remove the packing body (including packing gland, packing ring, packing, etc.) or mechanical seal parts;
(3) After removing the O-ring seal, the shaft sleeve, the balance plate and the key on the shaft in turn, remove the water outlet section, the final guide vane, the balance ring sleeve, etc.;
(4) After removing the last stage impeller and the flat key, remove the middle section and guide vanes; follow this order to remove the various stages of impeller, middle section and guide vanes until the front impeller is removed;
(5) After removing the pump coupling, unscrew the coupling nut of the water inlet section and the bearing body and the bolts on the bearing gland, and then remove the bearing parts on the side of the water inlet section;
(6) Pull the shaft out of the water inlet section, unscrew the fixing nut on the shaft, and remove the bearing inner ring, O-ring seal, and shaft sleeve in turn;
(7) For pumps with sliding bearings, the disassembly sequence is basically the same, only slightly different when disassembling the bearing parts.
Installation of D-type horizontal multi-stage pump
In addition to meeting general requirements when installing this type of pump, the following points should also be noted:
1. The foundation plane for installing the pump should be leveled with a spirit level. After the foundation cement has solidified, check whether the base and anchor bolt holes are loose.
2. After the motor, pump and base are assembled, the concentricity of the pump shaft and the motor shaft should be strictly checked to ensure that the two shaft centers are on the same axis;
3. When assembling the motor and the water pump, the shaft extension of the pump coupling end should be pulled out to ensure the axial clearance value between the end faces of the coupling halves of the pump and the motor;
4. The pump can only bear its own pressure and cannot bear any external force, so the suction pipe and pressure pipe of the pump should have their own brackets to avoid crushing the pump.
5. DMD pumps used in mines containing combustible and explosive gases must use explosion-proof motors and require corresponding explosion-proof grades and explosion-proof marks.
