Flowserve VTP Wet Pit - Manual (Page 45)

VERTICAL TURBINE PUMPS (VTPS) CENTRIFUGAL PUMPS ENGLISH 71569224 – 10-13
Page 45 of 76 flowserve.com
Typical allowable field vibration values 5.7.7.2
for vertical turbines with suction barrel
Motor rating kW (hp)
Vibration
velocity-
unfiltered Vibration
mm/sec (in./sec)
rms
0.75-to 7.5 (1-10) N 5.1 (0.20)
7.5 to 75 (10-100) N 5.1 (0.20)
75 to 750 (100-1000) N 5.1 (0.20)-6.1(0.24)
750 to 2250 (1000-3000) N 6.1 (0.24)-7.1(0.28)
N = Normal; Alarm = N X 1.25; TRIP = N X 2.0.
Motor start/stop frequency 5.7.8
Even though motors are normally suitable for at least
two consecutive starts, it is recommended to restart
only after coasting to rest between starts (minimum
of 15 minutes gap), with the motor initially at ambient
temperature. If more frequent starting is necessary,
refer to driver manufacturer’s instructions or contact
Flowserve with details.
The number of motor start and stops
in any given time affects motor life.

If the motor is expected to experience multi
starts in any given time, please refer to the driver’s
user instructions before the pump is put into
operation.
Operating the Pump 5.8
Venting the pump 5.8.1
Make sure that the pump is vented to enable
all trapped air to escape, taking due care with the
hazardous or hot liquids. Under normal conditions
after the pump is fully vented and primed, it should
be unnecessary to re-vent the pump.
Pumps fitted with packed glands 5.8.2
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 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 packing gland.
If hot liquids are being pumped it may be necessary
to loosen 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 40-60 drops per minute
is required.
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 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.
Pumps fitted with mechanical seal 5.8.3
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.
External flush or quench should be
started before the pump is run and allowed to flow for
a period after the pump has stopped.
Never run a mechanical seal dry,
even for a short time.
DISCHARGE VENT LINE
SUCTION VENT LINE
SEALING LIQUID
SUCTION
SOURCE