Flowserve WMV IDP - Manual (Page 12)

WMV, WMVS USER INSTRUCTIONS ENGLISH 26999970 10-12
Page 12 of 28
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Pumps should not be mounted with the motor below
the pump casing.
Where pumps are to be horizontally mounted, the
four mounting brackets (two left hand and two right
hand) are supplied in a separate package with the
necessary bolts for fitting.
The pump should be mounted with the air release
valve uppermost and the drain plugs in suction/
discharge casing on the underside.
a) To assemble, remove the two bolts from the
motor flange on the side opposite to the air
release valve and loosely bolt on two feet with
the bolts and washers provided.
b) Loosely bolt on the two remaining feet to the
holes in the suction/discharge casing.
c) Set the feet to the correct distance from the pump
axis given on the outline arrangement drawing.
d) Final positioning and locking of the feet should be
done with the pump in its installation position.
e) Where horizontally mounted pumps are handling
hot liquid we recommend that the brackets at one
end only are bolted down. The brackets at the
other end should be allowed to move freely on
the foundation.
4.4 Grouting
Where applicable, grout in the foundation bolts.
Foundation bolts should only be fully tightened when
the grout has cured.
4.5 Piping
Protective covers are fitted to the pipe
connections to prevent foreign bodies entering during
transportation and installation. Ensure that these
covers are removed from the pump before connecting
any pipes.
4.5.1 Suction and discharge pipework
Never use pump as a support for piping.
In order to minimize friction losses and hydraulic
noise in the pipework it is good practice to choose
pipework that is one or two sizes larger than the
pump suction and discharge. Typically main
pipework velocities should not exceed 2 m/s (6 ft/sec)
suction and 3 m/s (9 ft/sec) on the discharge.
Maximum forces and moments allowed on the pump
flanges vary with the pump size and type. To minimize
these forces and moments that may, if excessive, cause
misalignment, hot bearings, worn couplings, vibration
and the possible failure of the pump casing, the
following points should be strictly followed:

Prevent excessive external pipe load

Never draw piping into place by applying force to
pump flange connections

Do not mount expansion joints so that their force,
due to internal pressure, acts on the pump flange
Ensure piping and fittings are flushed
before use.
Ensure piping for hazardous liquids is arranged
to allow pump flushing before removal of the pump.
Take into account the available NPSH which must be
higher than the required NPSH of the pump.
4.5.2 Suction piping
a) The inlet pipe should be one or two sizes larger
than the pump inlet bore and pipe bends should
be as large a radius as possible.
b) On suction lift the piping should be inclined up
towards the pump inlet with eccentric reducers
incorporated to prevent air locks.
c) On positive suction, the inlet piping must have a
constant fall towards the pump.
d) The pipe next to the pump should be the same
diameter as the pump suction and have a
minimum of two pipe diameters of straight section
between the elbow and the pump inlet flange.
Where the NPSH margin is not large, it is
recommended that the pipe straight is 5 to 10
pipe diameter. (See section 10.3, Reference 1.)
Inlet strainers, when used, should have a net 'free
area' of at least three times the inlet pipe area.
e) Fitting isolation and non-return valves will allow
easier maintenance.
f) Never throttle pump on suction side and never
place a valve directly on the pump inlet nozzle.
g) Fit a foot valve to the end of the suction pipe when
the open tank liquid level is below pump level.
4.5.3 Discharge piping
a) A non-return valve should be located in the
discharge pipework to protect the pump from
excessive back pressure and hence reverse
rotation when the unit is stopped.
b) Fitting an isolation valve will allow easier
maintenance.
c) On boiler feed service, a pump discharge valve
should always be fitted in addition to the boiler
non return valve.