Oil change frequency

Q  -  How frequent should the lube oil in the bearing housing be changed?

A  -  A typical recommendation from a pump vendor is to replace the oil in the
bearing housing once a year for light service, once every six months in medium
service, or once every three months in heavy (or severe) service.

For this purpose, a light service may be defined as the continuous, or intermittent,
operation of small size (or low horsepower) pump, at low running speed (4-pole
motor speed, or less), in low operating temperature. A heavy service may be
defined as the continuous operation of large size (or high horsepower) pump, at
high speed (2-pole speed, or faster) in ambient, or high operating temperature.
Those in between may be considered to be in medium service.

The problem with this approach is that there is substantial overlap in what may be
considered as light, medium, or heavy service; the decision when to change oil
becomes subjective. This approach is also too simplistic and ignores the thrust
loads on the bearings, and the effects of worn-out running clearances, and that of
the rotor that can go out of balance.

The ideal solution is to implement a monitoring program whereby oil changes are
done at regular intervals, say once every three or six months initially, and carefully
monitoring for premature oil discoloration, or signs of viscosity breakdown, and
then adjusting the oil change interval accordingly. The need for more frequent oil
changes is an early indication of potential trouble, and the pump can then be  
scheduled for preventive maintenance to avoid costly breakdown.

When doing oil change, drain the bearing housing completely, flush with suitable
solvent, and refill with new oil. Use recommended lubricants only, and maintain
correct oil level - never overfill.

R: 0101-OICH
C: operation, maintenance
F: oil change

"Make it simple"

Related topic:
Constant level oilers





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