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For pumps with flammable pumping media in Zone 2, Zone 2 inside, or pumps for
Zone 1, Zone 1 inside, as well as pumps of the FZ and FPC series, the shaft seals
must be monitored on the basis of the ignition protection system type b1 according to
DIN EN ISO 80079-37 as follows:
Monitoring of a pump with a single mechanical seal:
The product supply (suction side) to the pump must be monitored in
such a way that
- the liquid flow is never lost
Monitoring parameters: Dry running inside the pump
- the pumping medium is supplied as described under point 3.1.2
- the max. permissible pumping media temperature is maintained.
-
An explosive atmosphere (zone 1 inside, zone 2 inside) inside
the pump is not permitted
Deviations from this require a separate manufacturer's approval
and can be found in the order-related documents!
Monitoring of a pump with a double mechanical seal with a seal
supply system:
The product supply (suction side) to the pump must be monitored in
such a way that
- the pumping medium is supplied as described under point 3.1.2
- the max. permissible pumping media temperature is maintained
- the pump is only operated for a short time (<30 s) without the
pumping medium
deviating dry running times can be found in the order-related
documents if applicable
- no ignitable mixture can form inside the pump unless the pump is
designed for this purpose.
Monitoring parameters: Dry running inside the pump
The sealing medium supply to the seal must be monitored in such a
way that
- the flushing flow never breaks off, or there is a continuous sealing
medium on the seal
- For pumps with an explosive atmosphere (Zone 1 inside, Zone 2
inside) within the pump head, a monitored forced
circulation/flushing system must be provided.
Deviating supply plans must be approved by the manufacturer
and may be found in the order-related documents.
- The sealing medium is compatible without foreign objects,
lubricating, harmless, of low viscosity and compatible with the
pumping medium, and there is sufficient differential temperature
(>25 K) to the boiling point.
