Dalton Utilities operations
personnel at the Loopers Bend WWTP were experiencing poor performance
from their existing progressive cavity sludge holding tank transfer
pumps. Excessive down time was a combination of major rebuilds
occurring every 4-6 weeks and the long lead time for repair parts.
The Utility’s Maintenance
Manager was looking for a more reliable cost effective pump, that when
service
was
needed, could be handled in a more efficient manner. He reported that
each pump’s annual service cost was approaching $15,000. Also, due
the design of the existing units, it was difficult to rebuild the
pumps in place. Unfortunately, budget constraints made a capital
purchase a challenge so they were interested in a “try it before you
buy it” approach. That way, they could be confident the replacement
pump lived up to the claims of lower frequency of required maintenance
and longer operation without the need to unclog. The Owner expressed
concern over the need to pump occasional rags and stringy material
that had caused problems in the past.
A
visit by Penn Valley to the plant determined that a retro fit was
feasible and that the piping modifications were simple enough to be
done in house by DUTIL personnel. Also, a unit could be shipped
within two weeks to satisfy the need to resume processing of stored
sludge. Penn Valley Pumps recommended an 8” model 8DDSx125CNU pump
driven by a 15 HP electric motor. Since the motor horsepower matched
the existing unit, DUTIL was able to use the existing VFD.
The first unit was placed
into operation in October 2009 and as of this posting July 2010, it
has yet to require any servicing or unclogging while operating as the
only active transfer pump in this process. The double disc design can
handle rags and variations in sludge consistency without issue and if
needed can be completely serviced in line with the need to remove
suction or discharge piping.
Penn Valley Pumps are
domestically manufactured and more information can be found at
www.pennvalleypump.com
