Flowserve QLQ Vertical Worthington - Manual (Page 39)

QLQ, QLQC USER INSTRUCTIONS ENGLISH 87900027 – 06/14
Page 39 of 61
The motor bearing temperature limitations should be
considered for its lubrication requirements. Refer to
the driver manufacturer’s user instructions supplied
with the pump. If documents are not found contact
Flowserve.
For thrust bearing lubrication, please refer to Section
5.3 of this manual.
Never mix greases containing different
bases, thickeners or additives.
5.8.7 Normal vibration levels, alarm and trip
Pumps generally fall under classification of rigid
support machines within the International Rotating
Machinery standard and maximum vibration levels
are based on those standards.
Vibration shall be recorded placing the
accelerometers on the thrust bearing house. If the
pump is not equipped with thrust bearing, vibration
shall be taken placing the accelerometers on the
flange joining the pump head and the driver.
Here below you can find the sketch indicating the
measurement points, according to API 610 standard.
To compare the vibration levels during the
pump life and with the recorded level during factory
acceptance test, the points of measurement shall be
kept according to the sketch below.
Measuring vibration levels in other points will make
the level not comparable.
Alarm and trip values for installed
pumps should be based on the actual measurements
(N) taken on the pump in a fully commissioned (new)
condition. Measuring vibration at regular intervals
and recording will help to track any deterioration in
pump or operating conditions.
5.8.7.1 Typical allowable field vibration values
According to Flowserve experience, the following
values can be taken as a guideline to set the
alarm/trip of the pumps.
 Up to 7 mm/s RMS (0.275 in/sec RMS): vibration
level acceptable
 Between 11 and 12 mm/s RMS (0.43-0.47 in/sec
RMS) the pump must be trip
These values are referred to the
measurement taken according to API requirements
(see above). Measurement taken on the motor
bearings ( DE or NDE) will result in higher values.
5.8.8 Motor start/stop frequency
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.
5.9 Running or operation
5.9.1 Venting the pump
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.