5
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.
6.3.3. Foundation Properties
The foundation shall be horizontal, flat and clean and shall support all the
weight.
NOTE:
Reinforced concrete bases are constructed from standard
concrete with at least B 25 resistance class.
Mn.
20
m
m
Mould
Base
Mortar
Key
Leave a min. 20mm space under the base
make wet before applying mortar
Leave the surface of the base rough and
Concrete base
Figure 2. A typical concrete foundation
6.3.4. Fixing (Securing) of Pump Group
After the alignment of the pump group on the foundation has been made,
the mutual securing bolt screws should be used alternately to fix the
pump group.
All of the area of the base plate should be filled with gout as much as
possible.
NOTE:
While securing pump group with the mortar bonding agents and
molding, one has to make sure that the base plate contacts completely
with the base with no cavities between the surfaces. Inside of the chassis
(frame) should be completely filled with concrete
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 smooth edged metal pieces (e.g. a steel ruler or a gauge stick)
and one precision calipers. (Figure 3.)
(For more precision alignments, special apparatus can be used).
Coupling misalignments in general are of two kinds:
1. Paralel axis misalignment
(Figure4 - 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.
Install the coupling guard only when the alignment of the coupling is
checked
.
Figure 3
. The control of the coupling alignment in horizontal and vertical
planes.
90
90
90
Y
1
X
1
