Centrifugal pump is an indispensable facility in the production process. During the production and operation process, it is inevitable that the centrifugal pump needs to be disassembled due to overhaul, maintenance and other reasons. Here are some matters needing attention in the disassembly process. Safety requirements for disassembly of centrifugal pump; 1. implement safety measures for the work ticket (the fitter workshop implements the system of "six exits, one no contact and one review"). 2. before disassembling the main pump, check whether the tools and lifting machinery (e.g. down chain, overhead crane and steel wire rope) are in good condition. Basic conditions for disassembly of centrifugal pump: Familiar with the structure, especially for complex pumps or new pumps. Before disassembly, the drawings or instructions must be checked to understand the function, relationship and rotation direction of each component, so as to avoid blind disassembly. Mark them to avoid misalignment. Before disassembly, adjacent parts or coupling parts must be marked to avoid vibration caused by incorrect or uneven reassembly quality (such as multiple keys on the shaft, couplings, etc.). When marking, mark on the non working surface. Before maintenance, carefully measure and record the data. Such as alignment data of pump and motor. The disassembly sequence is reasonable. First remove the auxiliary parts of the pump (auxiliary pipes, circulating cooling water system, couplings, etc.), then remove the main engine, remove the outside first, then the inside, remove the upper part first, and then the lower part. Please select appropriate tools before disassembly, and design and make special tools if necessary. Do not knock during disassembly. Protect all threads, mating surfaces and top holes of the shaft. The parts shall be neatly arranged to facilitate assembly. Disassembly sequence of centrifugal pump: 1. remove the fixing bolts of the coupling guard, and then remove the coupling guard. 2. make a mark on the coupling (the old pump shall be marked again), and measure the alignment data of the pump and motor. 3. remove the connecting bolts. 4. remove the cooling water pipe. 5. remove the mechanical seal gland bolts, and then release the remaining liquid in the seal. 6. drain the lubricant from the bearing housing. 7. Remove the connecting bolts between the pump cover and the pump housing. 8. lift the pump body. 9. remove the impeller back cover and impeller. 10. remove the bolts connecting the pump suspension and pump cover, and then remove the pump cover. 11. remove the pump side coupling. 12. loosen the front seal ring and rear seal ring of the pump bearing housing. 13. remove the pump bearing housing (install the impeller back cover before disassembly to avoid damaging the threads of the shaft head.) 14. remove the bearing back cover, remove the bearing, and then remove the bearing gland. 15. remove the sealed shaft sleeve. And the movable ring is on the sleeve. 16. check and clean all parts, and prepare the parts and materials to be replaced.