Motor Bearings, Bme Hp Feed Pump; Automatic Monitoring Devices, Bme Hp Feed Pump; Shutting Down The Bmex; Shut-Down Procedure - Grundfos BMEX Serie Instrucciones De Instalación Y Funcionamiento

18. Motor bearings, BME hp feed pump

Under optimum operating conditions, the operating life of the
motor ball bearings is approx. 20,000 operating hours. After that
time, the bearings must be replaced. The new ball bearings must
be filled with grease.
BME hp feed pumps have grease nipples for manual greasing.
For greasing intervals, etc., see motor nameplate or the
installation and operating instructions supplied with the motor.
19. Automatic monitoring devices, BME hp feed
pump
The system must be fitted with a low-pressure switch on the inlet
pipe to the BM hp circulation pump to ensure a minimum/
maximum inlet pressure.
The inlet pressure switch should be set to:
Min.: 1 bar
Max.: 35 bar.
Furthermore, it is recommended to install a high-pressure switch
on the discharge side. This switch stops the system if the normal
operating pressure is exceeded to an unacceptable level.
The discharge high-pressure switch should be set to:
BME hp feed pump: max. 80 bar (without time delay).
BM hp circulation pump: max. 80 bar (without time delay).

20. Shutting down the BMEX

To prevent overpressurisation, suitable pressure relief valves
should be fitted and procedures implemented to ensure that the
high-pressure side of the X-Changer module is depressurised
prior to isolation of the low-pressure side.

20.1 Shut-down procedure

See section

21. Periods of inactivity

when shutting down the system. These precautions must be
taken to protect the system and ensure long life of all the system
components.
This section makes references to the piping and instrumentation
diagram, fig. 16.
Procedure:
1. Stop the BME hp feed pump (P3).
2. Wait until the system pressure drops below 28 bar (400 psi).
3. Stop the BM hp circulation pump (P4).
4. Stop the sea-water feed pump (P1).
5. To avoid corrosion in the BME hp feed pump, flush the system
with fresh water (P2) for minimum 10 minutes (min. 2 bar for
flushing) or until the salinity is below 500 ppm, Total Dissolved
Salinity, TDS.
6. Start the BM hp circulation pump (P4). Run the system for 5 to
10 minutes until all the sea water is purged. A minimum
pressure of 2.0 bar (29 psi) is required to feed the X-Changer
low-pressure inlet. The fresh-water flush will not occur without
this minimum pressure. Continuous operation of the BME hp
feed pump (P3) is not recommended during the fresh-water
flush procedure, however, momentary operation of the pump
will help purge sea water from the X-Changer module and
membranes.
7. Stop the BM hp circulation pump (P4).
8. If a BME hp feed pump is to be shut down for an extended
period of time, the system must be thoroughly flushed with
fresh water to remove any salt. Precautions should also be
taken to inhibit biological growth. The system units should
receive a final flush with the same solution used to preserve
the membranes.
for precautions to be taken

20.2 Flushing the BME hp feed pump

The pump must be stopped during flushing.
The pump can be flushed through in or against the flow direction.
See fig. 16.
Flush the system through with fresh water for approx. 10 minutes
or until the salinity is below 500 ppm. The pressure during
flushing must be minimum 2 bar. The flushing must be continued
until the pump is completely filled with clean fresh water.
If the flushing takes more than 10 minutes, the flow
Note
must be reduced to maximum 10 % of the rated flow.
The pump must be filled with clean fresh water
Note
during periods of inactivity.
To flush the pulley head of the BME hp feed pump,
start the pump for 30 seconds to allow the fresh
Note
water to enter into the pulley head.

20.3 Flushing the BM hp circulation pump

The pump must be stopped during flushing.
When a BM hp circulation pump is flushed, the flow must be
reduced to maximum 10 % of the rated flow rate if flushing takes
more than 10 minutes.
21. Periods of inactivity
In the case of periods of inactivity, various precautions must be
taken to protect the system and ensure long life.
The precautions to be taken if the system is to be inactive for a
certain period appear in the table:
Action
Flushing, see section
20.2 Flushing the BME hp feed
pump.
Fill the pumps with fresh water.
Preserve the pump.*
Slacken and remove the V-belts.
Preserve the pulleys against
corrosion, see section
21.1 Preservation of pulleys and
belts.
Rotate pump and motor shafts
manually once a month.
* Use the same solution that is used to preserve the
membranes.
The normal stop procedure must be followed step by
Caution
step.
x x x x
x x x x
x x x
x x x
x x
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