Adjusting pump clearance

Using slip speed parameter, when adjusting pump clearance.

Service visit, adjusting the pump clearance

Schematics drawing of the pump impeller and the adjustment screw.

The case has two redundant Sulzer pumps for wastewater transport, type ABS XFP 26.9 kW.

Once annual the pump clearance is adjusted, as part of the annual service and maintenance program.
Normally, and according to guidance from pump manufacturer:
Loosed the adjusting grub screws and tighten the securing screws in the bottom plate evenly until the impeller will lightly, but freely, rub against the bottom plate when rotated by hand”.

The plots show the monitored magnetic field strength and the slip speed, before and after the pump clearance adjustment has been performed.

The monitored slip speed change during clearance adjustment can be used for adjusting according to desired value. This can eventual be use of the initial settings, also monitored and recorded with the EWA sensor.