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Product Overview

ManualsBrandsGrundfos ManualsIndustrial PumpsCR 3-11 Multi-Stage In-Line Circulator, 2 HP, A-FGJ-A-E-HQQE Seal, 3 PH, 208-230/460V, ANSI Flanged
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Improve efficiency with the right pump
Getting the best possible overall efficiency out of your pump
makes financial sense. The narrow interval between CR pump
sizes allows you to eliminate the efficiency drop associated
with over-dimensioned pumps.
By minimising the difference between pump capacity and
the required pressure and volume, you get a pump which runs
as close to its optimum duty point as possible. That makes it
as cost-efficient as possible. And the CR family is sure to have
exactly the right match for you.
Careful research behind real improvements
These days, pumps have evolved to a point where extremely
small margins decide their final efficiency level. Always keen
to accept a challenge, the Grundfos hydraulic engineering
teams have carried out painstaking research into fluid dy-
namics to break new ground and find new ways to improve
the CR.
The result of their development work is very concrete: a 10%
increase in pump efficiency. This translates into a power re-
duction of 15-20% for the CR pumps. When your pumps are
in operation many hours a day, such improvements provide
substantial savings – year in and year out.
Internal leakage caused by pressure differentials
within the pump was minimised. Tests on pumps
similar to a CR3 have shown that an impeller seal
clearance gap of just 0.1 mm between the impeller
and the chamber causes a 5% drop in efficiency. The
reason for this efficiency loss is quite simply that
when liquid seeps out into the pump, precious energy
is wasted on circulating that liquid. To reduce internal
leakage to an absolute minimum, Grundfos uses a
floating seal ring between chambers. This provides a
close to perfect seal.
1
A 10% increase in pump efficiency is an
impressive result, and it was not achieved
in one go. It took three innovative improve-
ments to create the total effect.
All good things come in threes
EFFICIENCY
10
0 1 2 3
m
3
/h
4 5
20
30
40
50
60
70
Zero impeller seal clearance gap (theoretical)
1/10 mm impeller seal clearance gap
3/10 mm impeller seal clearance gap
%