UNIREX Pump - Manual (Page 47)

MARK 3 USER INSTRUCTIONS ENGLISH 71569102 08-06
Page 47 of 68 flowserve.com
Figure 6-18
6.8 Examination of parts
6.8.1 Cleaning/inspection
All parts should now be thoroughly cleaned and
inspected. New bearings, O-rings, gaskets, and lip
seals should be used. Any parts that show wear or
corrosion should be replaced with new genuine
Flowserve parts.
It is important that only non-flammable,
non-contaminated cleaning fluids are used. These
fluids must comply with plant safety and environmental
guidelines.
6.8.2 Critical measurements and tolerances
To maximize reliability of pumps, it is important that
certain parameters and dimensions are measured
and maintained within specified tolerances. It is
important that all parts be checked. Any parts that do
not conform to the specifications should be replaced
with new Flowserve parts.
6.8.3 Parameters that should be checked by
users
Flowserve recommends that the user check the
measurements and tolerances in figure 6-19
whenever pump maintenance is performed. Each of
these measurements is described in more detail on
the following pages.
6.8.4 Additional parameters checked by
Flowserve
The parameters listed below are somewhat more
difficult to measure and/or may require specialized
equipment. For this reason, they are not typically
checked by our customers, although they are
monitored by Flowserve during the manufacturing
and/or design process.
6.8.4.1 Shaft and sleeve (if fitted)
Replace if grooved, pitted or worn. Prior to mounting
bearings or installing the shaft into the bearing
housing, check the following parameters:
Diameter/tolerance, under bearings
In order to ensure proper fit between the shaft and
bearings, verify that both the inboard (IB) and
outboard (OB) shaft diameter is consistently within
the minimum/maximum values shown in figure 6-20.
A micrometer should be used to check these outside
diameter (OD) dimensions on the shaft.
6.8.4.2 Bearings
It is recommended that bearings not be re-used after
removal from the shaft. Prior to mounting bearings,
check the following parameters:
Diameter/tolerance, inside diameter
In order to ensure proper fit between bearings and
the shaft, verify that the inside diameter (ID) of both
the IB and OB bearing are consistently within the
minimum/maximum values shown in figure 6-20. An
inside caliper should be used to check these ID
diameters on the bearings.
Diameter/tolerance, outside diameter
In order to ensure proper fit between bearings and
the bearing housing, verify that the OD on both the IB
and OB bearings are consistently within the
minimum/maximum values shown in figure 6-21. A
micrometer should be used to check these outside
diameter (OD) dimensions on the bearings.
6.8.4.3 Impeller balancing
Shaft whip is deflection where the centerline of the
impeller is moving around the true axis of the pump.
It is not caused by hydraulic force but rather by an
imbalance with the rotating element. Shaft whip is
very hard on the mechanical seal because the faces
must flex with each revolution in order to maintain
contact. To minimize shaft whip it is imperative that
the impeller is balanced. All impellers manufactured
by Flowserve are balanced after they are trimmed. If
for any reason, a customer trims an impeller, it must
be re-balanced. See note 1 under figure 6-19
regarding acceptance criteria.
6.8.4.4 Bearing housing/carrier
Prior to installing the shaft into the bearing housing,
check the following parameters:
Diameter/tolerance, at bearing surface
In order to ensure proper fit between the bearing
housing/carrier and the bearings, verify that the ID of
both the IB and OB bearing surfaces are consistently
within the minimum/maximum values shown in figure
6-21. An inside caliper should be used to check
these ID dimensions in the bearing housing.