Flowserve QLQ Vertical Worthington - Manual (Page 49)

QLQ, QLQC USER INSTRUCTIONS ENGLISH 87900027 – 06/14
Page 49 of 61
When mounting anti-friction bearings on the pump
shaft guide sleeve it has to be remembered that the
satisfactory operation of anti-friction bearings requires
that the inner is firmly held on the sleeve so that it
cannot turn on the sleeve.
Heat the bearing to expand the inner race and shrink
it on the sleeve.
Place the bearing on a shelf in a temperature
controlled oven, A temperature of 80°C (175°F) for
one half hour should be sufficient.
Care must be taken to keep the bearing clean and
uncontaminated.
Check the position of the bearing on the sleeve with a
feeler gage to make sure it is pressing firmly against
the shoulder.
In case the pump is equipped with tilting
pads bearings, please refer to dedicated instruction
provided with the specific pump documentation or
refer to the nearest Flowserve center for advice.
6.8.5 Maintenance of the bearing house (if
provided)
Thoroughly flush and clean the oil passages. Remove
all scale and deposit in the water circulation coil (if
installed) by chemical treatment when necessary.
6.8.6 Maintenance of bowl assembly
When repairing a bowl assembly that has
been in service for several years, the physical
condition or strength of all parts such as cap screws,
bowls and bowl threads must be carefully checked.
When attempting to rework any part,
extreme care must be taken to maintain alignment of
mating parts and ensure “as new” tolerances.
The inspection, disassembly of bowl assembly
requires expertise and tools to perform the job
correctly. It is recommended to seek the services of
Flowserve trained technicians to inspect and repair
bowl assemblies.
6.8.6.1 Maintenance of casing
The casing waterways should be kept clean and clear
of rust.
New O-rings shall be installed whenever the pump is
disassembled.
6.8.6.2 Maintenance of impeller
Clear all passageways and check for signs of
damage from abrasion or corrosion. Replace an
impeller that shows signs of excessive wear.
Slightly eroded parts can be repaired by welding.
Dynamically balance impellers after any machine or
repair work
6.8.7 Maintenance of seals
6.8.7.1 Replacing packing (when provided)
A good grade of graphite braided asbestos free
packing shall be used. Do not under any
circumstances use flax packing in the pump, as rapid
wear of the sleeve may result.
Inspect shaft or sleeve for score marks or rough spots.
Be sure by-pass holes (if supplied) are not plugged.
Repair or replace badly worn shaft or sleeve.
The following procedure shall be followed in repacking
the stuffing box.
1. Loosen the stuffing box gland.
2. Remove the old packing with a packing puller and
clean the stuffing box.
3. Make sure the packing to be used is of correct
type and size. Measure stuffing box to determine
proper length of packing. Packing should be cut
long enough (approximately 1.5 mm longer than
measured) to endure that the OD of the packing
rings hugs the stuffing box rather than the sleeve.
4. Oil inside and outside of replacement rings lightly
and Insert each ring of packing separately,
pushing it as far as possible into the stuffing box
and seating it firmly. Stagger the rings so that the
joints are 90° or 180° apart.
5. After inserting the required number of rings of
packing, the seal cage can be inserted. It is
important to make sure it is located directly under
the sealing connection and that the insertion of
successive rings will not displace it.
6. Continue adding more rings of packing. When the
required number of packing rings has been
inserted, install the gland and tighten the gland
nuts by hand; then back off the nuts until the gland
is loose. In tightening the gland the nuts should be
brought up uniformly so that the gland will not be
cocked and so that the packing is subject to
uniform pressure.