Servicing The Product; Technical Data; Operating Conditions; Liquid Temperature - Grundfos NK Serie Instrucciones De Instalación Y Funcionamiento

6. Servicing the product

Service on the pump end can be made on site. The
pump end does not need to be shipped to an
approved ATEX workshop.
Strictly observe the following check list.
It may be overruled by stricter local
maintenance schedules.
1. Check on a daily basis that the shaft seal and
auxiliary units function correctly.
2. Check for oil leakage around the bearing shaft
daily. If there is any oil spillage on the shaft
packings, it may be due to one of the following
reasons:
– The bearing bracket is overfilled.
– The breathing hole in the filling plug is blocked.
– The shaft packing is defective.
3. Check the lubricant and bearing noise each
week. If the bearings begin to show signs of
wear, they must be replaced. Under optimum
operating conditions, the operating life of the
bearings can reach its designed life. After that
period, we recommend replacing the bearings.
4. Check coupling rubber parts every four weeks. If
they begin to show signs of wear, they must be
replaced, and alignment of the pump must be
checked.
5. Inspect O-rings for cracks, elasticity, and
permanent change of shape when doing periodic
maintenance or servicing the pump. Replace if
necessary.
6. It is the responsibility of the customer to do the
following:
– Decide whether to use the non-sparking tools
or to shut down the system for service.
– Lay down a cleaning scheme for pump
surfaces when you install it in a combustible
dust environment.
7. When cleaning a pump located in a combustible
dust environment, remember to take the shaft
guard and coupling guard off, and clean these
cavities.
8. Any standby pump installed must be switched on
once a week to keep it operational.
9. The pressurising or flushing system must be
thoroughly cleaned once a year. Read the
manufacturer's instructions for the auxiliary unit.
Take the pump out of operation for this purpose.
10. Torques for all fasteners can be found in the
service instructions for NK, NKG pumps.
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7. Technical data

7.1 Operating conditions

7.1.1 Liquid temperature

The maximum liquid temperature depends on the
temperature class specified by the customer and the
shaft seal.
Temperature class
T1
T2
T3
T4
T5
T6
The illustration below shows the maximum surface
temperature of the pump as a result of maximum
liquid temperature and temperature rise in the shaft
seal.
T [°C]
Fig. 12 Calculation of maximum surface
temperature
The maximum surface temperature of the pump must
be at least 5 °C lower than the maximum surface
temperature of the temperature class specified by
the customer.
The maximum liquid temperature and the
temperature class specified by the customer are
stated on the "key application data sheet" supplied
with the pump. See the example at the end of this
document.
Maximum surface
temperature
[°C]
450
300
200
135
100
85
Maximum surface
temperature of the
pump
Temperature rise in
the shaft seal
(determined by
Grundfos)
Maximum liquid
temperature