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The Practical Pumping Handbook .........

continuously to prevent cold joints and voids under the baseplate. The
grout should then be allowed to harden in accordance with the
manufacturer's instructions.
It should be noted that vibrations from machines operating close at
hand is often transmitted into the foundation of the pump being
grouted. These machines should be shut down until the grout takes its
initial set, otherwise the bond of the grout may be detrimentally
affected. To identify the presence of local vibrations, place a shallow pan
of water on the pump baseplate and observe the surface for movement.

10.1.7 Epoxy based grouting
The use of epoxy grout is steadily increasing in a number of industries.
The increased bond strength helps to maintain the alignment between
the pump and driver, thereby reducing misalignment failures and
maintenance costs. Mso, as the surface is nonporous, it facilitates
cleanup in the event of an accidental spill.
Prior to using an epoxy grout however, the foundation must be clean
and dry. The grouting materials should also be stored at temperatures
between 70 and 90~ for at least 24 hours before mixing, and it should
be poured at temperatures between 40 and 90~

10.1.8 Pregrouted baseplates

In recent years some considerable success has been achieved with using
pregrouted baseplates to eliminate many of the traditional problems
identified with onsite baseplate leveling and grouting. Baseplates are
grouted in an upside-down position in the factory which reduces epoxy
grout volumetric shrinkage that can otherwise cause baseplate
distortion. They have been shown to travel better and arrive at the site
flat and aligned, just as they left the factory. They have also been
installed on site with the pumps and motors still in place.

10.2 Piping considerations

Piping layout design is an area where the basic principles are frequently
ignored, resulting in problems such as hydraulic instabilities in the
impeller, which translate into additional shaft loading, higher vibration
levels and premature failure of the seal or beatings.
As there are many other reasons why pumps could vibrate, and why
seals and beatings fail, the trouble is rarely traced to incorrect piping.
The main difficulty is that inadequate piping locates the root cause of
many pump failures outside the physical confines of the pump itself,
thus making it difficult to detect for the unwary and inexperienced.

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