Failure of fire-fighting equipment during an operation can lead to catastrophic consequences, and of course the same is also true for submersible pumps. For this reason, we have designed our NAUTILUS submersible pumps to be especially robust, resistant and service-friendly.


Checking the slide ring seal

Profile of the submersible pump NAUTILUS

Profile of the NAUTILUS submersible pump

The motor has to be well protected against the penetration of water via the shaft! In the case of NAUTILUS submersible pumps, this is ensured by two safety levels between the impeller situated in the water and the motor. A slide ring seal acts as the first sealing level, a shaft sealing ring the second. Between these two sealing elements is a channel that leads to an inspection opening in the pump cover. Via this, the maintenance engineer is able to check the slide ring seal for leaks after every operation. If the slide ring seal begins to leak during use, the downstream shaft sealing ring will protect the engine from water ingress for the duration of use – thus operation will not be interrupted.

Note: Do not allow the pump to run dry for an extended period of time, otherwise the seals may wear unnecessarily.

How to check the slide ring seal (for example TP 4/1 or 4/1 ECO):

  1. Remove the locking screw from the inspection opening.
  2. Seal the discharge outlet with a blind cap.
  3. Place the pump in a container filled with approx. 30 cm of water.
  4. Connect the mains plug to the power supply.
  5. Make sure the pump is running by listening for the usual operating noise.
Inspection opening of the submersible pump NAUTILUS

Inspection opening of the NAUTILUS submersible pump

Check whether water is discharged out of the inspection opening.

  1. If water is discharged: slide ring seal is defective
    • Disconnect the mains plug from the power supply immediately.
    • Re-attach the locking screw to the inspection opening.
    • The pump must be repaired by an authorized workshop.
  2. If water is not discharged: slide ring seal is OK
    • Let the pump run for 5 minutes.
    • If there is still no water discharge, disconnect the mains plug from the power supply.
    • Re-attach the locking screw to the inspection opening.
    • The pump is ready for the next operation.


Flushing the pump after use

Among others, the high flow rates and pressures of our submersible pumps are the result of the special geometries and the smallest possible distances between impeller and diffuser. To ensure that no dirt causes it to seize up during storage, flush the submersible pump with clear water after each use.


Simple removal of an impeller blockage

Removing an impeller blockage of the submersible pump NAUTILUS

Removing an impeller blockage of the NAUTILUS submersible pump

IMPORTANT: prior to this measure, you must disconnect the submersible pump’s plug from the mains, otherwise the pump will restart automatically after the impeller has been freed! Observe the safety instructions in the operation manual.

There are nine holes in the floor plate of the NAUTILUS. If the impeller is blocked by foreign objects such as stones, pieces of wood or the like, it is possible to turn the impeller in both directions using a screwdriver WITHOUT removing the bottom plate. This releases the impeller blockage and the pump can be put back into operation without further effort.