Horizontal Multistage Centrifugal Pump Disassembly & Assembly: Step-by-Step Guide

For the disassembly and assembly of horizontal multistage centrifugal pumps, first ensure operational safety through process reversal and pressure relief, then disassemble pump body components step by step in the order from external to internal, and from high-pressure end to liquid inlet end. Before operation, operators must wear appropriate personal protective equipment to ensure their own safety.

Disassembly of a Horizontal Multistage Pump

I. Process Reversal and Pressure Relief

Shut down the pump  

1. Close the inlet and outlet valves of the pump.  

2. Open the vent valve to release residual pressure.  

3. Open the filter blowdown valve to fully drain the medium in the filter.  

II. Pump Body Disassembly

1. Remove the flange bolts at the high-pressure output end.  

2. Remove the connecting nuts of the high-pressure end bearing gland, take off the high-pressure end bearing end cover, then remove the connecting nuts of the bearing bracket and detach the bearing bracket. 

3. Remove the lock nut of the high-pressure end bearing, take off the high-pressure end bearing with a puller, remove the high-pressure end bearing inner cover and bearing rubber sleeve, then take off the inter-shaft sleeve and bearing cover plate.  

4. Remove the packing gland bolts and pull out the gland axially.  

5. Remove the nuts at both ends of the tie rods, pull out the connecting tie rods of each pump section. Remove the fixing screws of the flanges at both ends of the balance pipe and take off the balance pipe.  

6. Take out the stuffing box axially, then remove the packing, packing sleeve seal and packing sleeve.  

7. Take out the balance disc and balance disc key axially.  

8. Remove the anchor bolts at the high-pressure pump head end and take out the high-pressure pump head axially.  

9. Take out the next-stage impeller axially and mark it with chalk. Tap the flange of the liquid outlet section with a copper rod and hammer to loosen it before removal. To prevent the liquid outlet section from falling due to vibration during disassembly, place a wooden block under it in advance. When disassembling each stage in sequence, mark the relative positions between sections beforehand and place them in order.  

10. Disassemble the liquid inlet end bearing housing: first remove the connecting nuts of the liquid inlet end bearing gland, take off the liquid inlet end bearing end cover, then remove the connecting nuts of the liquid inlet end bearing bracket and detach the liquid inlet end bearing bracket.  

11. Remove the sealing packing gland, take off the lock nut, remove the liquid inlet end bearing with a puller, take off the liquid inlet end bearing inner cover and bearing sleeve, remove the connecting nuts of the packing gland, pull out the gland axially, then take out the packing and packing sleeve.  

12. Disassemble the pump shaft by pulling out the bearing housing and pump shaft together.

Installation of a Horizontal Multistage Pump  

1. Clean all disassembled components.  

2. After cleaning, follow the reverse order of the disassembly steps (from Step 12 back to Step 1) to install the horizontal multistage pump.