Michigan township replaces complex pumps with simpler, more efficient models
The Ada Township, Mich., utilities department was experiencing frequent unscheduled maintenance visits and corresponding unbudgeted repair bills for the pumps at the township’s main pump station.
The existing pumps were complex and had many moving parts to maintain. Each included a main pump assembly, a seal pot mechanical seal system connected to an air compressor, couplings, shafting with pillow block bearings, shaft guards and vertical electric motors on the top floor. The routine maintenance of these machines was a big job in itself, but when vibration and failing seals became a recurring problem, the township looked for a solution that would put a stop to the expensive repairs and maintenance.
Ada Township, in conjunction with its engineering firm Moore & Bruggink, contacted Kennedy Industries for assistance. Based on its extensive experience with Flygt dry pit submersibles, Kennedy Industries recommended that the township install three Flygt model NT-3315 130-hp dry pit submersible pumps to deliver 1,400 gpm at 205 ft total dynamic head.
The township’s mechanical contractor changed out the pumps one unit at a time. The contractor first removed one of the old pumps, shafting, pillow block bearings, guards, seal-water pots, seal-water piping, air compressor lines, an air compressor and vertical motors on the grade floor.
Installation of the Flygt dry pit submersible was much simpler, since the self-contained Flygt pump does not require installation of a seal-water system, shafting, coupling, guards or any other auxiliary items. The pumping assembly is designed for continuous operation in either a non-submerged or fully submerged environment. The motor is inverter-rated per NEMA MGI, Part 31, and is available as premium efficient. Flygt dry pit pumps come standard with seal-fail and high-temperature monitoring, and if a seal failure were to occur in a Flygt pump, all leakage is contained in the pump—not spilled on the floor or flung on the walls.
A hard iron (25% chrome) impeller and insert ring is standard on all pumps above 10 hp. This material upgrade provides up to ten times better wear resistance when compared to standard cast iron, alleviating any concerns about grit and sand in the pumped media.
Flygt dry pit submersible pumps offer the innovative “N” impeller technology, a self-cleaning design that provides true non-clog pumping while reducing energy costs by 25% or more when compared with conventional pumps.
In addition to saving energy and reducing the cost of maintenance and operations, Flygt dry pit submersible pumps improve operator safety, since there is no longer a need to maintain 25-ft-long shafting or pull the pumps out for frequent repair.
The Flygt dry pit submersible pumps have produced savings through increased energy efficiency, reduced scheduled and unscheduled maintenance costs and improved safety for operations and maintenance personnel.
Maintenance requirements have been dramatically reduced, as the Flygt dry pit submersible pump requires no seal water, seal-water piping, solenoids, drains, shaft alignment, pillow block bearing adjustments, guard painting or bearing maintenance. Unlike the old conventional pumps, the Flygt pumps are submersible and would be unaffected in the event of a station flood.
The Flygt submersible pumps run smooth, cool and quiet. Clogging impellers, shaft misalignment, vibration, seal failures, extreme noise, abrasive media wear and bearing maintenance are all things of the past.