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6.4 Foundation
Grundfos recommends to install the pump on a concrete founda-
tion which is heavy enough to provide permanent and rigid sup-
port to the entire pump. The foundation must be capable of
absorbing any vibration, normal strain or shock. As a rule of
thumb, the weight of the concrete foundation should be 1.5 times
the weight of the pump.
Fig. 5
Example of a concrete foundation
Bolt hole dimensions are according to NEMA standard. Secure
the pump to the foundation using all four bolt holes. Uneven sur-
faces can result in pump base breakage when the mounting bolts
are tightened. (NEMA = National Electrical Manufacturers' Asso-
ciation).
To prevent vibrations from being transmitted to the building and
pipework, it is recommended to fit expansion joints and vibration
dampers.
Fig. 6
Expansion joints and vibration dampers on pump
6.5 Pipework in general
When installing the pipes, ensure that the pump housing is not
stressed by the pipework. The use of pipe compound or teflon
tape on all male threads (SR pumps) or a gasket (SF pumps) is
acceptable as a means of providing a positive seal at the pump
port conditions.
According to good installation practice, we recommend that:
•
the system is thoroughly cleaned and flushed of all foreign
materials and sediment prior to pump installation
•
the use of unnecessary fittings, valves or accessory items is
avoided, especially in the vicinity of the pump suction and dis-
charge ports
•
the piping is adequately supported to reduce thermal and
mechanical stresses on the pump
•
the pump is not installed at the lowest point in the system due
to the natural accumulation of dirt and sediment; if there is
excessive sediment or suspended particles present, we advise
you to use a strainer to prevent its entry into the pump
•
all pipework is done in accordance with the recommendations
of the US Hydraulic Institute.
6.6 Suction piping
The suction pipe should be adequately sized and run as straight
and short as possible to keep friction losses to a minimum. Avoid
using unnecessary fittings, valves or accessory items.
Care should be taken to provide a means of pump isolation (e.g.
gate or butterfly valves) in applications where the pump is in a
pressurized or flooded suction condition.
If the pump is installed in a suction lift application, horizontal suc-
tion piping must rise gradually from the source to the pump and
contain no high spots which allow air pockets to form.
Fig. 7
Suction piping
6.7 Discharge piping
Before the pump is installed, we recommend that the discharge
piping is pressure-checked to at least the maximum pressure the
pump is capable of generating or as required by local codes and
regulations.
According to good installation practice, we recommend that:
•
a check valve and isolation valve is installed in the discharge
pipe
•
pipe, valves, and fittings are at least the same diameter as the
discharge pipe or sized in accordance with good piping prac-
tices to reduce fluid velocities and pipe friction losses.
Pipe, valves and fittings must have a pressure rating equal to or
greater than the maximum system pressure.
The standard discharge position for SR, SF pumps is vertical
(upward). To simplify pumping connections, however, the pump
housing may be rotated to optional positions in the field.
The pump housing can be rotated to any of four positions at
90-degree intervals as shown in fig. 8.
Fig. 8
Repositioning pump housing (viewed from suction
end)
Reposition the pump housing as follows:
1. Loosen and remove each of the nuts that attach the pump
housing to the pump head.
2. Carefully lift the pump housing off the pump head and rotate it
to the required position. Check that the O-ring is properly
seated.
3. Apply thread sealant, Loctite 567 or like, to the staybolt
threads.
4. Reinstall the nuts and tighten diagonally and evenly.
5
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