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Special pumps

9.1 Sump pumps

When a sump or wet well has to be pumped out frequently, or have the
level controlled on a regular basis, a variety of pump styles are available
to do the job. The actual pump selected will depend on a number of
factors including the past experience of the engineer, the size and type
of operation, and the budget. As we have no control over most of
these, let's consider the various pump styles that are in popular use in
various industries.

9 1.1 Vertical sump pump
The sump pump is suspended from a sole plate mounted across the top
of the sump, with the wet end submerged below the level of the liquid
in the sump. The nature of this design lends itself to these applications
where the sump should be covered for safety or other reasons, as the
sump cover can be designed to act as a base for the pump soleplate.

This style frequently uses the same impeller and casing as end suction
pumps. The back cover and stuffing box are replaced by a cover fitted
with a steady bushing while the shaft is changed to the long column
shaft that runs up inside the column assembly. That assembly
accommodates the sleeve bushings, and both the column itself, and
lineshaft bushings are usually spaced at 1ft. and 3ft. intervals.
Depending on the nature of the liquid being pumped, the lineshaft
bushing can be lubricated by the pumpage, or by an injection of grease
or oil. The outside lubricants are delivered to the bushings through
tubes which are connected to the pump soleplate for ease of
lubrication.

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