8
Until the liquid starts moving against atmospheric
pressure, the hydrostatic pressure for self-priming
pumps must not exceed 1 bar with reference to
the difference in height between suction and
outlet liquid level and to the density of the pumped
liquid.
The pump must never be operated for
a longer period if the outlet stop valve
is closed. The pump unit will be
damaged if the pumped liquid exceeds the
permitted temperature.
5.3 Restarting
Do not restart the pump until the pump shaft
stands still.
Backflow of liquid must not result
in a change of direction of
rotation of the pump. If this is the case,
mechanical seals dependent on direction of
rotation may be damaged.
5.4 Stopping Operation
Close stop valve of the pressure pipeline. If there is
a backflow stop and sufficient counter pressure in
the pipeline, the stop valve can remain open.
Switch off the motor and observe that it slows down
smoothly. Close stop valve of the pressure pipeline.
If the pumped liquid reaches temperatures below
zero and/or if longer periods of standstill occur,
the pump must be drained completely and be
preserved (see section 2.2.1).
6 Service/Maintenance
6.1 Supervision of Operation
Ensure that the pump runs free of vibration and
smoothly
The pump must by no means be operated without
liquid.
There is only a minimal or invisible loss of leakage
(steam) if the mechanical seals function correctly.
Gland packings should drip slightly.
Do not operate the pump for a longer period with
a closed stop valve.
The maximum permitted environmental
temperature is 40oC. The storing temperature
measured at the motor or pump casing may
exceed the environmental temperature by 50oC. It
must not exceed 90oC. Only operate the pump at
a higher temperature with the manufacturer's
approval.
We have to point out that an increased wear may
occur in case of transport of abrasive / corrosive
media.
In case of corrosive / abrasive
media to be pumped pressurized
components have to be checked regularly in order
to detect wear in time - before a damage occurs.
The intervals have to comply with the liquids to be
pumped and initially have to be carried out more
frequently, until perceptions about the progress of
wear are attained.
CAUTION
Installed pumps must be powered on and off
briefly once a week in order to guarantee that they
are ready for operation.
6.1.1 Shaft Bearing
Under normal operation conditions, replace the
motor bearings after 20.000 hours of operation or
at the latest after 2,5 years. In the case of bad
operation conditions, as e.g. a high environmental
temperature or a corrosive and dusty
environment, the motor bearings must be checked
at an earlier date and, if necessary, be replaced.
CAUTION
Pump bearings with a lubrication device must be
checked every 5000 hours of operation. Dirty
bearings must be cleaned and filled with new
lubricant. The free space in the bearing and
casing should be filled by 30-50% with lubricant.
Do not use resinous or acid lubricants. Its
consistencies (NLGI grade) should correspond to
a worked penetration of 265 to 295 mm/10.
Lithium-base soap lubricants with a drop point of
more than 185°C are to be used for pumped
liquids which have a maximum temperature of
110°C. For pumped liquid with a higher
temperature, use silicon lubricants with a lithium-
base soap and with a drop point of more than
215°C.
If necessary, the bearings can also be lubricated
with lubricants of a different soap base. For this
based on different soaps must not be mixed. The
required re-lubrication periods must then be
adapted to the type of lubricant used.
6.1.2 Mechanical Seal
The mechanical seals are maintenance-free. If
leakages occur after a longer period of operation,
replace the complete seal.
6.1.3 Gland Packing
Gland packings are low-maintenance parts and
must leak slightly during operation. Do not tighten
a gland packing after its first operation.
Considerable leakage at the beginning disappears
by itself.
If greater leakages occur during operation, the
gland lid or insert must be slightly tightened,
however it must never be tightened at a slant.
