Mas Grup
4
6.2. Type of Connection
Type of connection depends on the design type and the size of the pump
and the motor, as well as the local installation conditions. Foot-mounted
horizontal pump-motor units have been installed in a common base plate.
6.3. Foundation
6.3.1. General
Base plate of the pump must be grouted. The foundation shall be of
concrete or steel framework.
NOTICE:
The foundation shall distribute the weight of the pumping group
evenly.
6.3.2. Main Properties of the Steel Framework Bases
Foundations with steel framework shall be designed in such a way that
the base plate is bolted or welded contacting to all area.
CAUTION
If base plate is supported from only four points, pump group will stay in
the middle, causing misalignment of the coupling and increasing the noise
level.
6.4. Coupling Alignment
6.4.1. General
For a proper operation of a pump group, a good alignment of the coupling
is necessary. Vibration, noise, overheating of the bearings, overcharge
problems can be attributed to the misalignment of coupling or using an
improper coupling.
Flexible coupling does not correct the axial misalignments between
the pump and the motor axes. However, it allows pinpointing the
misalignments.
In order to avoid overheating, vibration, noise and wearing of the
rolling bearings, alignment of the coupling has to be made properly
and checked often.
Do not use a different coupling other than the original type installed
on pumping group.
6.4.2. Method of Coupling Alignment
In order to make the alignment of the coupling, it is required to have at
least two pieces of about 10 cm tall, smooth-edged metal parts (e.g. a
steel ruler or a gauge stick) and one precision calipers. (Figure 4) (For
more precision alignments, special apparatus can be used).
Coupling misalignments in general are of two kinds:
1. Paralel Axis Misalignment
(Figure 4-Figure 6)
In order to control parallel axis misalignment, a smooth edged gauge stick
is pressed axially over the upper half of the coupling. Then, the gauge
stick is checked for the other half of the coupling. For alignment, the
gauge stick shall be in contact with both of the halves at the same time.
This procedure shall be repeated for four sides of the coupling. (i.e. top,
bottom, left and right sides of the coupling). When all four sides give
reasonably accepted results, alignment of the coupling has been
ensured.
2. Angular Misalignment
(Figure 5-Figure 7)
In order to control the angular misalignment, the distance between the
two halves of the coupling is measured in both horizontal and vertical
planes. Measurements taken at four points shall be in agreement for the
alignment.
Misalignments can be in horizontal or vertical planes. Misalignments
in horizontal plane can be fixed by placing sheet iron at the bottom
of the pump or motor base, while misalignments in vertical plane
can be fixed by sliding the pump or the motor in horizontal plane.
Figure 3:
The Control of the Coupling Alignment in Horizontal and
Vertical Planes
Figures below illustrate the possible coupling misalignments and
the methods to correct them.
Figure 4:
Paralel Axis Misalignment in Vertical Plane and Its Correction
Figure 5:
Angular Misalignment in Vertical Plane and Its Correction
Figure 6:
Parallel Axis Misalignment in Horizontal Plane and Its
Correction
Figure 7:
Angular Misalignment in Horizontal Plane and Its Correction
