Flowserve LNN - Manual (Page 23)

LNN, LNNV, LNNC USER INSTRUCTIONS ENGLISH 71569074 06-14
Page 23 of 56
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5.5 Priming and auxiliary supplies
Ensure all electrical, hydraulic,
pneumatic, sealant and lubrication systems (as
applicable) are connected and operational.
Ensure the inlet pipe and pump casing
are completely full of liquid before starting continuous
duty operation.
5.5.1
Suction pressure above atmospheric
pressure
Horizontal pumps: open vent connection (1) on top of
the pump upper casing to allow the trapped air to
escape. Let liquid run out until free from air bubbles.
( 1 ) P o s s i b l e
p r i m i n g
p o i n t s
Vertical pumps: open vent connection (1) at the front
of the upper half casing and disconnect the seal flush
line at the mechanical seal/stuffing box to allow the
trapped air to escape. Let liquid run out until free
from air bubbles.
5.5.2
Suction lift with foot valve fitted
Fill suction pipe and casing with liquid at a pressure
of 1 to 2 bar from an external source. Vent as
described in section 5.5.1.
5.5.3
Suction lift without foot valve
Pump casing vents on the suction volute must be
connected to an external vacuum pump priming
system. If in doubt please consult Flowserve.
P os s i bl e
pri m i ng
poi nt s
T o vac u um
pum p
5.6 Starting the pump
a) Ensure flushing and/or cooling/
heating liquid supplies are turned ON before
starting the pump.
b) CLOSE the outlet valve.
c) OPEN all inlet valves.
d) Prime the pump.
e) Ensure all vent connections are closed
before starting.
f) Start motor and check outlet pressure.
g) If the pressure is satisfactory, SLOWLY open
outlet control valve.
h) Do not run the pump with the
outlet valve closed for a period longer than 30
seconds.
i) If NO pressure, or LOW pressure, STOP the
pump. Refer to section 7, Faults; causes and
remedies, for fault diagnosis.
5.7 Running the pump
5.7.1
Venting the pump
Vent the pump to enable all trapped air to
escape taking due care with hot or hazardous liquids.
Under normal operating conditions, after the pump
has been fully primed and vented, it should be
unnecessary to re-vent the pump.
5.7.2
Pumps fitted with packed gland
+ P
- P
If the pump has a packed gland there must be some
leakage from the gland. Gland nuts should initially be
finger-tight only. Leakage should take place soon
after the stuffing box is pressurized.
The gland must be adjusted evenly to give
visible leakage and concentric alignment of the gland
ring [4131] to avoid excess temperature.
(1) Possible
priming
points