English
14
Wilo AG 09/2005
inlet flange of the pump.
a) Avoid sharp elbows or sudden narrowing. Use
convergent
d
20° (total angle).
b) Arrange the pipework so that there are no air
pockets (no bulges).
c) If high points cannot be avoided in suction line,
provide them with air relief cocks.
d) If a strainer is necessary, its net area should be
three or four times the area of the suction pipe.
e) If an inlet valve is necessary, choose a model
with direct crossing.
4.4.2.2 Design of a suction lift line
The inlet pipe must be as short and as direct as
possible, never place an elbow directly on the
pump inlet nozzle.
a) Avoid sharp elbows or sudden narrowings. Use
convergents 20° (total angle) with upright gene-
rating.
b) Arrange that the suction pipework is inclined
upwards towards the pump ensuring that there
are no peaks.
c) If a foot valve is necessary, do not oversize it
because it would generate pulsations (valve bea-
ting).
4.4.3 Discharge piping
4.4.3.1 Design of a discharge line
a) If discharge line is provided with a divergent, its
total angle will be between 7° and 12°.
b) Install the discharge valve after the non-return
valve downstream.
The non-return valve will be set in the discharge
pipe to protect the pump from any excessive
pressure surge and from reverse rotation.
If necessary, a control manometer can be connec-
ted on the pipework.
4.4.4 Final checks
a) Check the tightening of anchor bolts. Tighten
them if necessary.
b) Check that protective covers on suction and
discharge flanges are removed.
c) Check that holes of pipework flanges are paral-
lel and correspond to those of the pump.
d) Tighten suction and discharge flanges.
4.5
Electrical connections
Electrical connections must be made by a quali-
fied Electrician in accordance with relevant local
national and international regulations. This
includes any grounding.
It is important to be aware of the EUROPEAN
DIRECTIVE on electromagnetic compatibility
when wiring up and installing equipment on site.
Attention must be paid to ensure that the tech-
niques used during wiring/installation do not
increase electromagnetic emissions or decrease
the electromagnetic immunity of the equip-
ment, wiring or any connected devices.
The motor must be wired up in accordance with
the motor manufacturer's instructions (nor-
mally supplied within the terminal box) inclu-
ding any temperature, earth leakage, current
and other protective devices as appropriate. The
Flooded suction configuration
Do not tighten flanges before the final
check (see § 4.4.4).
CAUTION!
Do not tighten flanges before the final
check (see § 4.4.4).
Installation of the control manometer
Do not tighten flanges before the final
check (see § 4.4.4.).
CAUTION!
CAUTION!
