Installation and operating instructions Wilo
–
SCPV pumps
22
9.2 Overhaul maintenance
9.2.1 General information
It is inevitable after long service that certain
components will become worn. Frequently it
is more economical to renew the worn
components completely, but where site
machining and engineering facilities are
available most components can be restored
if wear is not too far advanced.
It is impossible to be mandatory regarding
the periods at which major overhauls should
be undertaken as this will be dependent
upon the fluid being pumped, the site
operating conditions, and the length of
operational availability required.
The determination of when major overhaul
should be carried out will depend upon the
performance of the pump, i.e. its rate of
deterioration
by
reference
to
instrumentation,
during
the
current
operational period. If the hydraulic or
mechanical performance has deteriorated to
such an extent that no further deterioration
can be tolerated during the next operational
period, wearable components should be
renewed.
If related pair of components show a marked
degree of wear in relation to the rest of the
unit, then it may be sufficient to renew only
the heavily worn components. If the wear is
uniform throughout the pump, then all
wearable components may require renewal.
Measurements should be taken and recorded
of all wearable components at the first, and
every
subsequent
overhaul
period.
Reference to these records will enable an
accurate assessment of the rate of wear to
be made, and a reasonably accurate forecast
regarding when a particular component may
require renewal can be made. Information
regarding original design
dimensions and
clearances is furnished in data sheet. Any other
information if needed can be obtained on
application from Wilo Mather & Platt Pumps Ltd.,
Service Department, Chinchwad, Pune 19. Such
request must quote nameplate number and type
of the pump in question.
The parts most likely to be affected are:
1. Impeller Necks/Impeller.
2. Ball Bearings.
3. Neck Rings.
4. Bush Bush
Before commencing dismantling operations,
ensure that the following tools and tackles are
available:
A crane / chain pulley block suitable for handling
the weight of pumping unit.
A selection of ring and open-ended spanners in
British and Metric sizes.
Eyebolts in British and Metric sizes.
Cotton rope, wire rope and slings.
Hardwood and metal packing blocks.
Miscellaneous tools including a set of Allen
keys, drills, pin drivers, files etc.
Extractor / puller for bearing and coupling.
The torque value to be set for a particular size of
screw is dependent upon:
Material of screw
Parent metal
Whether the screw is untreated or plated
Whether the screw is dry or lubricated
The depth of the thread
