Goforth Williamson Inc. provides pumps, pump repair, and field services to industrial and municipal markets in the Southern United States. Over the past few years, GWI has completed several pump repairs for a company specializing in building maintenance services. This facility maintenance company supports a major Atlanta-based airline by performing maintenance services for the airline’s hangar. Not only does the facility maintenance group clean 6,000 aircraft each month, they are also responsible for maintaining the lift station located inside the airline’s hangar.
CHOPPER PUMP FAILURE LEADS TO PROBLEMS
In August 2015, the chopper pump operating in the hangar’s wastewater sump failed. The facility maintenance group sprang into action, pulled the pump out of the sump, and sent it to the GWI pump repair center for inspection. Inspection revealed the chopper pump needed a new impeller, a new cutter bar, and a rewind on the motor.
“Their chopper pump was completely worn out,” explains Andy Bramlett, sales and support representative for GWI. “The issue we were facing was a long lead time on replacement parts. The manufacturer of that chopper pump estimated a four to six week delivery for the parts we needed, and that was just too long to get that pump back up and running.”
There was no back-up sump pump, so the facility maintenance group had to temporarily reroute the flow. Because GWI is focused on providing solutions for their customers, Bramlett contacted the facility maintenance group to offer them another option.
“The facility maintenance group needed a sump pump, and they needed it fast, so I talked with them about the BJM Pumps line of submersible shredder pumps,” explains Bramlett. “They were open to replacing the chopper pump, so I contacted Steve Mosley, an applications engineer at BJM Pumps, to discuss a particular model of shredder pump that I had in mind for their lift station application.”
CRITICAL POINTS FOR PUMP SELECTION
Bramlett explained the critical points for pump selection were:
- Selecting a pump that could shred solids in the wastewater sewage. The lift station collected raw sewage from the airport hangar. This raw sewage coming out of the planes and from the hangar’s wastewater contained an excessive amount of “flushable” wipes and rags. The submersible pump would have to shred those solids and operate without clogging.
- Pump reliability. The lift station was designed with a simplex system; meaning only one submersible pump operated in the hangar’s wastewater sump. It was important to select a reliable submersible shredder pump to reduce maintenance and avoid downtime.
- Fast delivery. The submersible shredder pump would need to be delivered as soon as possible so the facility maintenances group could install a permanent solution into the hangar’s lift station.
THE SOLUTION
Mosley and Bramlett reviewed the pump curve and the system requirements. They selected an SKG Series Submersible Shredder Pump, the SKG37C-460, for the following reasons:
This SKG Series Submersible Shredder Pump is designed with dual shredding RAD-AX® technology, which would enable the pump to obliterate “flushable” wipes and other solids that saturate the sewage coming into the hangar’s wastewater lift station. This patent-pending design employs both radial and axial shredding components. A rotating cutter bar with serrated edges traps and shreds solids against the sharp grooves of a radial cutting ring while multiple axial cutting bars shred any leftover material exiting the radial cutters.
All the shredding components of the SKG37C Submersible Shredder Pump are manufactured in hardened 440C Stainless Steel, with a Rockwell hardness of 55C plus, giving it durable construction for improved wear resistance and longer service life.
The SKG37C Submersible Shredder Pump relies on a high-torque, four-pole motor to ensure difficult solids are handled more effectively. Because this particular 5-horsepower motor operates at 1750 RPM, the hydraulics of this pump matched the hydraulics of the original chopper pump; giving the end user the head and flow they required (up to 42 feet of head and a maximum of 410 gallons per minute).
Utilizing a two-vane, chrome iron impeller, the SKG37C Submersible Shredder Pump is extremely efficient for passing larger solids. The two-vane design also incorporates “pump out” vanes on its rear shroud to help protect the mechanical seal area from solids build up. The hardened impeller is resistant to wear, which translates into longer service life.
Protected by double mechanical seals, the motor has an oil-lubricated double seal design that utilizes an upper seal made of silicon carbide / carbon and a lower seal comprised of silicon carbide / silicon carbide. An additional lip seal is installed above the impeller to prevent the sewage from entering the seal chamber.
Built with superior motor protection, the SKG37C Submersible Shredder Pump is manufactured with a corrosion-resistant stainless steel motor housing. Winding protection is provided by (NEMA) Class F motor insulation and a built-in motor thermal switch. If amp draw and/or temperature gets too high, an automatic switch turns off the pump motor. The switch automatically resets when the motor cools, and the pump resumes operation.
The SKG37C Submersible Shredder Pump comes with a heavy-duty SOOW power cable and cable entry sealing system that utilizes an FKM compression fitting with a stainless steel gland nut to hold and seal the cable. This pump also features individually isolated and potted power leads to prevent wicking. The SKG37C also includes additional motor protection by utilizing the Seal Minder® Moisture Detection System to receive an early seal fail warning in case of moisture entering the mechanical seal oil chamber.
IN THE NICK OF TIME
Once the SKG37C was selected BJM Pumps informed Bramlett that the submersible shredder pump could be delivered in only two weeks’ time. Bramlett shared this information with the facility maintenance group; who then went to the airline for approval to purchase this pump. The airline promptly ordered the SKG37C Submersible Shredder Pump along with a discharge flange adaptor. The 3-inch ANSI adaptor flange allowed the facility maintenance group to attach the BJM Pump to the existing guide rail system.
“This was a very quick turnaround and a very painless process,” declares Bramlett. “The team at BJM Pumps was quick to respond, helped zero in on the right pumping equipment, and then did what they said they were going to do, which was to deliver the pump super quickly. The installation went smoothly, and the pump has been operating well since they put it into the lift station in September last year.” ◆
Kelly McCollum is a regional manager for BJM Pumps. BJM Pumps, headquartered in Old Saybrook, Connecticut, has been providing fluid handling solutions for industrial and municipal services since 1983. Over its thirty-year history, BJM Pumps has grown quickly by supplying world class pumps and accessories, priced competitively, through its global network of stocking distributors. For more information, visit www.bjmpumps.com.
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MODERN PUMPING TODAY, May 2017
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