How to Replace Davies MVI Vertical Multistage Cartridge Seal

Davies MVI Seal Replacement

  • Turn pump off and electrically isolate. All electrical work must be done by qualified electrician and comply with relevant electrical standards.
  • Remove side coupling finger guard covers.
  • Undo main coupling bolts and remove, along with drive pin.
  • Undo 4x motor bolts and lift motor away.
  • Undo 4x cap screws holding the seal cartridge on to pump housing.
  • Lightly release small grub screws holding shaft lock ring.
  • Use small flat blade screwdriver under cartridge flange to lift seal up off the shaft.
  • Install new seal in place over shaft and push down firmly, tighten down with 4x cap screws.
  • Ensure pump shaft is sitting fully down and tighten shaft collar lock grub screws. Pump shaft should be able to lift 3mm.
  • Lift pump shaft and slide plastic seal packer under shaft collar to set pre-load at 1.5mm.
  • Sit motor into place, motor spigot will locate motor, tighten 4x motor bolts.
  • Tighten 4x coupling cap screw firmly.
  • Remove plastic packer and give it a spin by hand to ensure it is free turning.
  • Fit covers, prime pump and re start.