Examination Of Internal Components - Wilo -SCP Einbau- Und Betriebsanleitung

9.3.1 Disassembling the top casing
• Isolate the pump system by closing suction and
delivery valve.
• Drain the pump and open the upper air vent (27).
• Remove two steady pins(33) and the split flange
nuts.
• For gland packing:
• Remove nuts of split gland(15) from both ends
and slide away the gland(14). Remove gland
packing(12) as well as logging ring(13)
• For mechanical seal:
• Disconnect the flushing tubes(35), loosen the
nuts of the gland plate(14) and slide them away on
the shaft(4).
• Remove all studs(29) joining top & bottom
casing(1&2). Connect suitable lifting tackles to
the eye bolts(37) provided on top half casing(1).
Remove the casing gasket(31)
• Remove the paper gasket(31) placed in between
the two casing halves
9.3.2 Dismantling the rotating element (Gland pack
version pump)
• Remove the coupling screw/nut of the coupling
• Remove the screw of the bearing end cover (16 &
20)
• Remove the steady pin (33) and hex screw (36) of
bearing housing (18 & 25)
• Lift the rotor element
• Remove the coupling and coupling key(30)
• Remove bearing housings of both driving and non
driving ends (18 & 25)
• Now remove the lock nut (24) and lock washer
(23) from the shaft free end
• Remove the both driving and non driving bearings
(17 & 22) using puller (Never try to extract the
bearing by applying force to the outer race)
• Now remove the thrust collar(19) from the non
driving end of the shaft
• Remove the water thrower(32) from both sides of
the shaft(4)
• Remove the gland(14) and gland packing(12) from
the shaft along with logging ring(13)
• Remove the stuffing box bush(11) from both side
• Now unscrew and remove the sleeve nuts(10) and
spacer sleeves(9) on both side
• Carefully extract the o-ring(8) from the sleeve(7)
with suitable tool without damaging it
• Now remove the neck rings(5) from the impel-
ler(3)
• In order to remove the sleeves effortlessly, apply
some molly cream or grease on the shaft and slide
the sleeves over it(Also first clean the shaft prior
to the removal of the sleeves). Mark the position
of impeller(3) on the shaft(4) to ease the reposi-
tion it while reassembling.
• Now remove the impeller(3) carefully avoiding
damage to the impeller key(6)
• If difficulty is observed in removal of the impeller,
apply heat uniformly over the impeller shrouds
inwards towards the hub
Installation and operating instructions Wilo-SCP
9.3.3 Dismantling the rotating element (Mechanical
seal version pump)
The only difference between disassembly of gland
pack and mechanical seat version pump is the
disassembly of the mechanical seal
The procedure up to water thrower removal is
same as per gland pack version.
Disassembly of mechanical seal is as follows:
• Slide out the gland plate carefully over the shaft.
• Now mark the position of mechanical seal(12) on
the shaft(4) to ease the position while reassem-
bling
• Unscrew the grub screw of the seal adjusting ring
• Pull the mechanical seal carefully over the shaft
followed by removal of adjusting ring
• Rest procedure is same as explained for gland pack
version pump

9.4 Examination of Internal Components

With the disassembled rotating element, the
internal components and clearances can be che-
cked
9.4.1 Casing neck ring
Use an internal micrometer to measure the bore of
casing ring, taking measurements at intervals
around the circumference to check for uneven
wear. A comparison between this dimension and
that of the impeller neck will indicate the amount
of diametrical clearance between the casing neck
ring and the impeller neck. If this clearance is
150% or more than the original design clearance,
or if the deterioration in hydraulic performances
has been such that no further deterioration can be
tolerated during the next operation period, the
neck ring should be replaced.
The impeller-wearing ring to casing neck ring cle-
arance must be restored to the original design
value by fitting small- in-bore neck rings, bored
out to suit the diameter of the impeller.
9.4.2 Shaft Sleeves
The shaft sleeve should be examined to see if it is
grooved or generally worn. The outside diameter
of the sleeve should be measured and a compari-
son made with the bore of the stuffing box bush
through which the sleeve passes. The amount of
clearance between the two can thus be checked
to determine whether or not it is within accepta-
ble limits.
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