Edwards ATEX 1 EHR, Instruction Manual

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A750-04-880 Issue F
Page 18 © Edwards Limited 2012. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
INSTALLATION
3.5 Sealing liquid and seals flush supply system design
3.5.1 Introduction
Your pump may be supplied with a sealing liquid and (for ATEX Category 1 and 2 pumps configured for external seals
flush supplies) seals flush supply system fitted, configured in one of three ways, as described in Sections
3.5.2 to
3.5.4 .
If your pump is not supplied with such a system, you must install the pump in a supply system which:

Supplies sealing liquid to the pump.

On ATEX Category 1 and 2 pumps configured for external seals flush supplies only, provides seal flush supplies
to the seals in the pump, to cool the seals and ensure that the seals temperature remains within the
temperature classification of the pump (see
Section 1.3.2 ).
Your supply system must be configured in one of the following three ways (shown in Figure 1 ):

Total recirculation system: see Section 3.5.2 .

Partial recirculation system: see Section 3.5.3 .

Once-through system: see Section 3.5.4 .
If you need to install an ATEX Category 1 or 2 pump configured for internal seals flush supplies in a supply system,
your system design must ensure that:

The sealing liquid supply to the pump is clean.
If you need to install an ATEX Category 1 or 2 pump configured for external seals flush supplies in a supply system,
your system design must ensure that:

The seals flush pipelines provide seals flush liquid supplies to cool the seals in the pump.

On ATEX Category 1 the seals flush supplies cannot be interrupted; during pump operation. The supply
pipelines must incorporate flow switches in each of the seals flush supply pipelines and a pressure switch in
the seal flush supply manifold or a level switch if you are using a reservoir: refer to Sections
3.5.2 to 3.5.4
for more details.

On ATEX Category 2 the seals flush supplies cannot be interrupted; during pump operation. The supply
pipelines must incorporate flow switches in each of the seals flush supply pipelines: refer to Sections
3.5.2 to
3.5.4 for more details.

The sealing and seals flush liquid supplies to the pump are clean.
WARNING
You must not start the pump if the level of sealing liquid is above the pump centre line. To avoid
this, configure the pump as shown in
Figure 1 , detail A, B or C and start-up the pump as described
in Section 4.2 .