LDC multi-stage centrifugal pump

Product Description:

Design features

These multi-stage centrifugal pumps are designed from modular elements

Interchangeable for various sizes to render possible an economic spare Part Stock keeping.

Casing parts

The casing parts are sealed against each other by O-rings and secured by external tie bolts. Normally suction and discharge casings are designed with feet below. In the case of hot liquids beginning with size 80(t>1 50℃)and size 150(t>110℃)the feet are, however, positioned in pump central line.

Position of inlet and outlet pipes

Normally the outlet pipe is positioned upwards and inlet pipe is positioned to the right(from the direction of driving end). Alternative pipe positions is available and additional outlet pipe at the stage casings are possible.

Hydraulics model and compensation of axial thrust

Each size has two sets of different impeller/defuser(hydraulics model) ,thus an optimum efficiency is obtained in many ranges. Interchangeable wear rings seal the impellers towards the stage casings. The axial thrust produced by the single—suction impellers is compensated by a hydraulic balancing device.

A design with balancing disc ensures a complete compensation and the residual axial will be sustained by the bearing.

Bearing and lubrication

When the pump uses balancing disc structure, the bearings shall be lubricated by grease (using thin oil for specification above 50). When the pump uses balancing drum structure,  the bearings shall be lubricated by thin oil.

Shaft sealing  

Normally packing seal are used as shaft sealings, while chemical seal shall only be applied for balancing drum structure and the chemical seal shall be balancing type.

The pressure of liquid at the outlet end will decrease when it is balanced by the balancing disc and balancing drum, therefore the shaft sealing only bear the pressure of the outlet.

While the shaft sealing is flushed with sealing liquid, for liquid temperatures above 110℃, the stuffing box gland shall be cooled; the stuffing box shall be cooled when the temperature of sealing liquid is above 130℃.