Flowserve BP - Manual (Page 30)

BP USER INSTRUCTIONS ENGLISH 85392725 10-09 (E)
Page 30 of 44 flowserve.com
f) Bearing housing [3200, 3230) to stuffing box
[4112] and suction head [1222].
Also check the gasket seat faces and ”O” ring faces.
As a general rule all” O “rings and gaskets should be
replaced at major overhauls.
6.8.2 Impeller
a) Check whether crack, damage, erosion and
corrosion are found by liquid penetrate test or
visual inspection.
b) Check whether the bore of impeller fitted on the
shaft is worn and the impeller keyway is
deformed.
6.8.3 Impeller rings[ 2300], Stage piece ring
[1500], Diffuser rings [1610]
a) Check whether scores, galls, scratches, nicks,
biting of foreign materials, erosion and corrosion
in the mating surfaces are found by visual
inspection.
b) In general it is recommended that the rings be
replaced or overhauled when the original
clearance has doubled or when pump capacity
has fallen below to an acceptable minimum as a
result of ring wear.
See “Important Clearances and Movement Table” in
section 10.4 Technical Data Sheet.
Single-Ring Construction- In BP pump
using standard ring construction, wear of the casing
rings can be remedied by turning down the impeller
hub at the running joint until a good surface is
obtained and then boring a spare undersize (small
internal diameter) casing ring to suit. Clearance at
the running joint should be the same as that provided
between the original ring and the impeller. Another
remedy would be to bore out the casing rings
sufficiently to eliminate the worn surface
imperfections and then down the impeller hubs at the
running joint to receive an oversize(large outer
diameter) ring. The first of the above remedies is
recommended for initial running joint restoration.
Double-Ring Construction- Rings are sometimes
provided in both the casing and on the impellers if
specifically requested on the original order –this
construction is not standard. On double-ring units
renewal of the proper ring clearance can be
accomplished by turning down the impeller rings to a
slightly smaller diameter and by replacing the casing
rings with undersize rings. The next repair should be
made boring out the casing rings with oversize rings.
By alternately or re-machining the ring sets, each ring
can be used two or more times.
6.8.4 Balancing Device
is recommended that replacement be made when the
clearance between the balancing drum O.D [6700]
and the bore of balancing ring I.D [1600] has
increased 50% or where there is a noticeable drop in
pump capacity. The balancing ring is installed on the
bore of the discharge head [1221] with shrink fit. A
dowel pin is pressed into the hole drilled between the
periphery of the balancing ring and the bore of the
discharge head to prevent the loosening and rotation
of the balancing ring. See “Important Clearances and
Movement Table” in section 10.4 Technical Data
Sheet.
6.8.5 Shaft
When the pump is dismantled, examine the shaft
carefully. Its condition should be checked at the
impeller hub fit, under the distance sleeves, and the
bearings. The shaft may become damaged by rusting
or pitting due to leakage along the shaft at the
impeller or distance sleeves. Anti-friction bearings
improperly fitted to the pump shaft will result in the
inner race rotating on the shaft thus causing undue
damage. Check the shaft keyway for distortion.
Excessive thermal stresses or corrosion may loosen
the impeller on the shaft and subject the keyway to
excessive shock. After a shaft has been repaired,
check it for possible run out 0.05 mm (0.002 in) T.I.R.
6.8.6 Mechanical Seal
a) Check sliding contact material for nick, scratch
and abrasion.
b) Check parts for dirt, scale and other matters.
c) Check packing and “O” ring for scratch and
deformation.
d) Sealing face should be re-lapped or replaced.
Packing and “O” ring should be replaced. Refer
to the instruction manual for mechanical seal for
further details.
6.8.7 Thrust bearing shoe [3032]
Check the mating surfaces of the shoes if they have
any grooves, wear or melting. If the wear, grooves or
scratches are minor they can be repaired. If the
damage is severe they have to be replaced with new
ones. If the thrust shoes are to be repaired, they
must be checked and confirmed by micro-meter to be
the same thickness.
Thrust shoes have to be replaced with a
complete set.
6.8.8 Thrust Collar [3610]
Check the thrust faces of the collar for any scorings
or burrs. If the scorings or burrs are minor it can be
repaired.