Grundfos NB 80-200/222VAXEF1BESBQQEWX2, Installation And Operating Instructions Manual

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5.5 Pipes
5.5.1 Pipe installaiton
When installing the pipes, the pump housing must not
be stressed by the pipes.
The inlet and outlet pipes must be of an adequate
size, taking the pump inlet pressure into account.
The pipes must be installed in a way that air pockets
are avoided, especially on the inlet side of the pump.
TM002263
Pipelines
The isolating valves must be fitted on either side of
the pump to avoid having to drain the system if the
pump needs to be cleaned or repaired. The pipes
must be adequately supported as close to the pump
as possible, both on the inlet and the outlet side. The
counterflanges must lie true against the pump flanges
without being stressed as stress would cause
damage to the pump.
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TM053310
Pump installation
5.5.2 Direct mounting in pipes
To ensure quiet operation, suspend the
pipes from suitable pipe hangers.
Pumps fitted with motors up to and including frame
size 132 are suitable for direct mounting in supported
pipes.
TM053337
Direct mounting in pipes
This type of installation does not allow the use of
expansion joints.
5.5.3 Bypass
DANGER
Explosion hazard
Death or serious personal injury
‐
The pump is not allowed to run against
a closed valve except during startup.
Operating against a closed valve at an
extended period of time will cause an
increase in temperature and the
formation of steam and may result in
damages to or explosion of the pump
housing. The valve must be kept open
during operation.
If there is any danger of the pump running against a
closed valve, ensure a minimum liquid flow through
the pump by connecting a bypass or drain to the
outlet pipe. The minimum flow rate must be at least
10 % of the maximum flow rate. The flow rate and
head are stated on the pump nameplate.
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English (GB)