Axial thrust in double suction centrifugal pump

[Daren Samy]

Theoretically, axial thrust in double suction closed impeller centrifugal pump is zero. But vendor always recommends 0.15mm-0.20mm axial clearance on non drive end side of pump. Why is it so? Does double suction centrifugal pump feels thrust due to motor and if so then why?

Daren!

 

[JJPellin]

If everything is symmetrical, the net thrust should be close to zero. The thrust bearing requires clearance, set when it is cold. When the thrust bearing heats up in operation, it needs room for thermal growth of the bearing and associated hardware.

Johnny Pellin

 

[Daren Samy]

This is the reason which is embarrassing. I have recently overhauled double suction centrifugal pump where designer has suggested 0.15mm axial clearance on non drive end of pump.

Daren!