Operating
Instructions
10
1096.0833 | CY, CSY, LNY, LSY, NPY, PY, Y, YS Series
05/2011
3.2 General description
Pumps of the CY, CSY, NPY, LNY, LSY, PY, Y and YS series
are single-stage, horizontal centrifugal pumps in close coupled
version.
The extended motor shaft of close coupled versions
simultaneouly serves as pump shaft, on which the impeller and
the mechanical seal is installed. The impeller is designed as
peripheral impeller and is floating on the motor shaft. The pump
casing is directly screwed to the motor flange.
These pumps are used for the delivery of pure, aqueous liquids
which do not contain abrasive or fibrous particles.
Type
Self-priming
Not
self-priming
CY, NPY, LNY, Y
x
PY, LSY, CSY,
NPY, YS
x
Tab. 7
Priming behaviour
Fig. 3
Peripheral impeller pump
3.3 Design and functional principle
1 Impeller
2 Casing
3 Casing channel
4 Interrupter
Fig. 4
Mode of operation of a peripheral impeller pump
The impeller (1) of a peripheral impeller pump is designed as
disc and has radial blades at the outer diameter, which are
milled into the front and back side of the circumference.
On both sides of the impeller blades, channels are arranged
circularly inside the casing (3), through which the medium flows.
These circular channels (3) are interrupted between the casing
inlet and outlet (4) to prevent an overflow from the discharge to
the suction side.
The hydraulic power is transmitted by momentum exchange
between the impeller and the casing channel. Thus, relatively
high pressures can be generated with small geometries.
3.4 Shaft sealing
3.4.1
Mechanical seal
Mechanical seals may slightly leak for functional reasons.
The pumps are equipped with the following mechanical seal
types:
•
Single mechanical seal, unbalanced, dependent on the
direction of rotation
•
Single seal (bellows seal), unbalanced, independent of the
direction of rotation, rotating spring (cylindrical spring)
