Storage Procedures / Preventing a Seized Pump

Issue: AquaSeal pump/system is seized. Motor works but pump impeller will not turn.

Each DEKKER vacuum system is tested and checked at the factory prior to shipment to ensure trouble free operation and free spin of the impeller. Cast Iron models are prone to oxidization, which can be accelerated by humidity and standing water inside of the pump. If the pump will not be operated for more than 2 weeks, DEKKER strongly urges the end user to completely drain the pump, and store the pump with rust-inhibiting anti-freeze to prevent seizing of the moving parts due to surface rust. The clearances inside the pump, between the impeller face and the port plates are around 0.007” – approximately the thickness of 2 sheets of notebook paper.

Uncouple the motor from the pump if possible, to determine whether or not the pump has seized. If the motor shaft spins freely, but the pump shaft does not; the pump may have seized.

If an AquaSeal vacuum pump will not rotate, check the following items:

  1. Uncouple the motor from the pump to check free spin
  2. Look down the flanges to see if excessive surface rust has developed
  3. If the pump has been in storage for more than 30 days, remove one of the drain plugs and note the condition of any sealing liquid. Is it brown and rusty? Was the pump stored with rust-inhibiting anti-freeze?
  4. Seized pumps can be freed by applying penetrating fluid such as ‘WD-40’, or ‘PB Blaster


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