Flowserve Gearex Rotary Gear Pumps External and Internal Bearing - Manual (Page 31)

EXTERNAL GEAREX USER INSTRUCTIONS ENGLISH 71569246 (2167B-E1)
Flowserve Pump Division 31
®
3. When the above two methods are unsuitable, it is
necessary to vacuum prime the pump. This can
be accomplished with a vacuum pump or air
ejector. The priming line is attached to the upper
most portions of the discharge suction piping. To
prime, close the discharge valve and do not start
the driver until the pump and piping are full of
liquid. Provision must be made to seal the
stuffing box with sealing fluid to prevent in
leakage of air.
It should be noted that if a valve is not provided on
the discharge side of the pump it may be necessary
to prime the entire system to avoid excessive power
consumption on initial start-up.
5.6 Starting the pump
a) Ensure flushing and/or cooling/
heating liquid supplies are turned ON before
starting the pump.
b) OPEN 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) Do not run the pump with the
outlet valve closed.
h) If NO pressure, or LOW pressure, STOP the
pump. Refer to section 8 FAULTS; CAUSES
AND REMEDIES, for fault diagnosis.
5.7 Post start-up
Once the unit has operated satisfactorily for several
days record as much information about these normal
operating conditions as possible. This data may be
helpful in identifying and correcting changes in future
performance before serious problems occur.
Typical data to be recorded is: serial number of pump
and driver, suction pressure, discharge pressure,
specific gravity, capacity, pump speed, amperage
and voltage (each phase), seal liquid pressure,
ambient temperature and pumping temperature.
5.8 Dowelling
After the unit has been running continuously about
one week, the coupling halves of direct driven units
should be given a final check for misalignment
caused by pipe strains or temperature strains. If the
alignment is correct, both the pump and driver should
be dowelled to the baseplate. The pump should be
dowelled with one dowel in each support foot. Refer
to the manufacturer’s manual for driver dowelling
instructions.
5.9 Running the pump
5.9.1 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.
5.9.2 Pumps fitted with packed gland
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 pressurised.
The gland must be adjusted evenly to give
visible leakage and concentric alignment of the gland
ring to avoid excess temperature. If no leakage
takes place the packing will begin to overheat. If
overheating takes place the pump should be stopped
and allowed to cool before being re-started. When
the pump is re-started, check to ensure leakage is
taking place at the packed gland.
If hot liquids are being pumped it may be necessary
to slacken the gland nuts to achieve leakage.
The pump should be run for 30 minutes with steady
leakage and the gland nuts tightened by 10 degrees
at a time until leakage is reduced to an acceptable
level, normally a minimum of 120 drops per minute is
required. Bedding in of the packing may take
another 30 minutes.
Care must be taken when adjusting the gland
on an operating pump. Safety gloves are essential.
Loose clothing must not be worn to avoid being
caught up by the pump shaft. Shaft guards must be
replaced after the gland adjustment is complete.
Never run gland packing dry, even for
a short time.
5.9.3 Pumps fitted with mechanical seal
Mechanical seals require no adjustment. Any slight
initial leakage will stop when the seal is run in.
Before pumping dirty liquids it is advisable, if
possible, to run in the pump mechanical seal using
clean liquid to safeguard the seal face.