Should a Worn Pump Casing Be Repaired or Replaced?
When a pump casing handles slurry containing particles over an extended period, localized thinning, grooving, erosion, corrosion, cracks, or wear on sealing surfaces may occur. Once wear is detected on the pump casing, the location and extent of the damage should first be evaluated before deciding whether to repair or replace it.
During inspection, focus should be placed on: erosion and thinning of the pump casing's inner wall; localized wear on the volute or flow passages; suction and discharge ports; areas in contact with wear plates, liners, or seals; bolt holes and mounting surfaces; sealing surfaces; whether cracks, deformation, or leaks exist; and whether the wall thickness still meets operational requirements.
Whether minor localized wear can be repaired must be determined based on the pump casing material, pressure-bearing conditions, damage location, and repair process. When cracks, severe thinning, structural deformation, or damage to critical mating surfaces are involved, simple repairs may not restore the original structural integrity and safety conditions.
If a decision is made to replace the pump casing, the following should be verified: pump model and pump casing part/drawing number; inlet and outlet dimensions and orientation; mounting hole locations; fit with the impeller; fit with wear plates, liners, and seals; pump shaft centerline position; direction of rotation; and material requirements.
Do not judge whether a new and old pump casing are directly interchangeable based solely on external similarity. Critical dimensions, mating surfaces, and internal clearances must be confirmed before official installation.
