Non-Flammable Liquids; Flammable Liquids; Checking The Direction Of Rotation; Servicing The Product - Grundfos NB Serie Montage- Und Betriebsanleitung

5.2 Non-flammable liquids

EPL Gb/Db (category 2G/D)
If the operator cannot ensure that the pump is filled
with pumped liquid during operation, appropriate
monitoring, for instance dry-running protection, is
required to stop the pump in case of malfunction.
EPL Gc/Dc (category 3G/D)
No additional monitoring is required.

5.3 Flammable liquids

EPL Gb/Db, Gc/Dc
If the operator cannot ensure that the pump is filled
with pumped liquid during operation, appropriate
monitoring, for instance dry-running protection, is
required to stop the pump in case of malfunction.
Ventilation around the pump is also required. The
leakage rate of a normally working shaft seal is less
than 36 ml for each 24 hours of operation. A
minimum air exchange of 1.5 times per hour is
required.
CAUTION
Flammable material
Minor or moderate personal injury
- The responsibility for checking the
functions of the dry-running protection,
such as flow rate, sealing pressure and
temperature of the barrier or flushing
liquid rests with the installer or owner.
Increased leakage can be the indication of
shaft seal failure. For some types of liquids
the leakage will not be visible due to
evaporation.

5.4 Checking the direction of rotation

Never check the direction of rotation by
starting the pump, not even for a short
period, unless the pump has been filled
with liquid. This is to prevent temperature
rises resulting from contact between
rotating and stationary components, and to
protect the shaft seal against dry running.

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
functions correctly.
2. Any standby pump installed must be switched on
once a week to keep it operational.
3. 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 in installations with combustible dust.
4. When cleaning a pump in a combustible dust
environment, remember to take the shaft guard
off and clean the shaft cavity.
Fig. 10 Take the shaft guard off
5. Inspect O-rings for cracks, elasticity, and
permanent change of shape when doing periodic
maintenance or servicing the pump. Renew O-
rings if necessary.
6. Torques for all fasteners can be found in the
service instructions for NB, NBG and TP, TPD
products.
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