Hydraulic radial thrust

An impeller will produce hydraulic radial thrust due to its developed head. The
equation for calculating hydraulic radial thrust load is:

T = [ Kq x Kt x D2 x B2 x H x SG ] / [ 2.31 ]


T      -  hydraulic radial thrust load, pounds
q    -  empirical capacity factor
t     -  empirical radial thrust factor
2    -  outer diameter (OD) of impeller, inches
2    -  width of impeller opening at D2, inches
H      -  developed head, feet
SG   -  specific gravity of liquid
2.31 -  conversion factor

Values for K
q are [ * ] and Kt are [ * ]

This equation applies to radial flow - not to axial flow or to positive displacement

In mixed flow pumps, the thrust acts at some angle from the shaft centerline so it
has to be resolved to its radial and axial components. Many prefer not to do this to
simplify the calculation and to use a conservative value of radial thrust.

Radial thrust acts in radial direction (perpendicular) to the shaft and will cause the
shaft to deflect more. It is important to reduce radial thrust to minimize the shaft
deflection and prevent the premature failures of thrust bearings and mechanical

Radial thrust is used in evaluating shaft deflection, sizing and selection of thrust
bearing, and in vibration and critical speed analysis.

Steps that can be taken to reduce radial thrust are included in a full version of this
article [ * ].

[ * ] Some information are excluded.
Read more.

R: 0110-HYRA
C: design, operation
F: thrust radial
Related topics

Hydraulic axial thrust
Hydraulic radial thrust
Hydraulic radial thrust on single volute pump
Balance disk (disc)





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