Start-Up; Maintenance; Operation; Periods Of Inactivity And Frost Protection - Grundfos NKG Montage- Und Betriebsanleitung

6.2.3 External flushing fluid systems
Standard shaft seals: The flushing fluid flushes the seal
chamber and is led to a drain. The flushing fluid cools and
lubricates the seal faces effectively.
3/8" outlet
3/8" inlet
Fig. 7 Tandem seal arrangement with flushing fluid being led
away to a drain
The pumped liquid leaking through the primary seal is washed
away to the drain by the flushing fluid.
For external flushing fluid systems note these conditions:
• The flow rate of the flushing fluid should match the application
(recommended flow rate 25-200 l/h. A temperature increase of
20 °C of the flushing fluid could also be used as a control
parameter).
• The pressure of the flushing fluid must always be lower than
the pressure of the pumped liquid.
Cartridge seal: The flushing fluid flushes the cartridge seal and
is led to a drain. If the external flushing fluid inlet pressure drops,
the internal pumping function of the cartridge seal provides
sufficient circulation of the flushing fluid to cool and lubricate the
seal faces. The cartridge seal is self venting.
The flushing fluid supply must never be
Note
connected directly to the public water supply
system. Local regulations must be observed.

7. Start-up

See also installation and operating instructions for the standard
pump.
Before start-up, the seal chamber/cartridge seal
Caution
and the pump must be completely filled with
liquid and vented.
1. Connect the inlet and outlet of the seal chamber/cartridge seal
by means of a suitable pipe or hose connection.
See figures 2 and 4.
2. Start the pump, and check the direction of rotation.
See the correct direction of rotation on the motor fan cover.
The seal chamber/cartridge seal must always be
Caution
filled with flushing fluid during operation.
Dry-running will destroy the shaft seal.

8. Maintenance

See installation and operating instructions for NK, NKG pumps.

9. Operation

To ensure optimum function and performance, make sure that the
flow of flushing fluid is always sufficient, and check that the
elevated tank never runs dry of flushing fluid.
Depending on the pumped liquid, the quality of the flushing fluid
must be checked at regular intervals to ensure optimum
operation.

9.1 Periods of inactivity and frost protection

Warning
Pay attention to the directions of the vent holes,
and take care to ensure that the escaping liquid
does not cause injury to persons or damage to
the motor or other components.
When handling hot or hazardous liquids, special
attention should be paid to the risk of injury
caused by scalding hot liquid or hazardous
liquid.
Local safety regulations must be observed.
Pump
For general guidelines, see installation and operating instructions
for NK, NKG pumps.
Seal chamber
Unscrew the two connections (pos. 2 and 3, fig. 2).
The lower flushing-liquid connection functions as drain.
Cartridge seal
1. Unscrew the connections for flushing fluid (pos. 1 and 2,
fig. 4).
2. Empty the cartridge seal. This can be done in two ways:
• Blow out remaining liquid by means of an air gun or a similar
device. The pressure must not exceed the pressure rating of
the cartridge seal.
• Flush the cartridge seal by means of a glycol-water solution, if
applicable for the application. The pressure must not exceed
the pressure rating of the cartridge seal.

10. Service

When ordering spare parts, always state the pump nameplate
data to ensure that the correct parts are delivered.
If Grundfos is requested to service the pump, Grundfos must be
contacted with details about the pumped liquid, etc. before the
pump is returned for service. Otherwise Grundfos can refuse to
accept the pump for service.

10.1 Service kits and service instructions

See www.grundfos.com (WebCAPS), WinCAPS or Service Kit
Catalogue.

11. Disposal

This product or parts of it must be disposed of in an
environmentally sound way:
1. Use the public or private waste collection service.
2. If this is not possible, contact the nearest Grundfos company
or service workshop.
Subject to alterations.
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