Since 1978, Tencarva has provided a range of rotating process equipment as well as repair and field services to industrial companies and municipalities throughout the Southeastern United States. Over the past few years, Tencarva worked with a large chemical company in Tennessee that had frequent pump failures due to solids and PH issues in a waste pit application. Mechanical seal failure due to solids contamination was the main culprit.
The manufacturing facility had a sump that relied on two effluent pumps to transport wastewater out of the plant. While one pump had initially been intended to operate as a backup, both pumps had been operating continuously to accommodate the high flow rate into the wastewater sump. Solid materials, such as zip ties, plastic tags and bags, that entered the wastewater stream from drains throughout the production facility, would enter the wastewater sump and damage the effluent pumps.
When the first pump failed, it was sent to a Tencarva repair facility in Virginia. The repair technicians found that the plastic debris had become trapped on the backside of the pump impeller, causing the mechanical seal to fail. The mechanical seal failure allowed wastewater fluid to enter the motor, resulting in complete failure of the effluent pump.
The first effluent pump was repaired and reinstalled, but only lasted a month in the manufacturer’s wastewater sump. “They had an emergency spare, but that one failed after a few weeks,” explains Ben Stolt, Branch Manager for Tencarva Machinery. “We learned the manufacturer’s in-house maintenance team had set up a back-up diesel pump in case both effluent pumps failed at the same time. At that point, we provided them with a BJM submersible shredding pump to use as an emergency spare.”
Stolt, who had seen videos of solids being shredded by BJM Pumps, worked with Steve Mosley, an inside Applications Engineer at BJM Pumps, to select an explosion-proof, submersible, corrosion-resistant shredder pump for the manufacturer’s wastewater sump. It was a priority for the manufacturer to keep workers safe; and with the potential for an explosive atmosphere, the plant required pumps with explosion-proof motors. The XP-SKX submersible shredder pump was chosen for its FM Approved explosion-proof motor (for use in Class I, Division 1, Groups C & D hazardous locations) as well as its ability to effectively shred and pass large solids.
“There’s a constant flow into this wastewater sump, and even though it’s 30 feet deep, it’s critical that this sump doesn’t overflow,” shares Stolt. “We were confident the XP-SKX was going to pump reliably in that sump because it’s made of 316 stainless steel, has a cutting impeller with a Tungsten Carbide Tip to shred solids, and an epoxy-coated motor housing – which was needed because of the high pH of the pumped fluid.”
While the XP-SKX was initially meant to be a “temporary” solution, it continued to operate reliably in the sump – even as the original effluent pumps continued to fail. Over the course of a year, the more expensive effluent pumps failed a dozen times; using up valuable maintenance dollars. “For the cost of 2 pump rebuilds, they could have purchased 1 new BJM Pump,” explains Stolt. “But the manufacturer had to see the BJM Pump in action before realizing they’d save money switching over to a different type of pump.”
After dealing with excessive pump failures, the manufacturer decided they could achieve more reliable pumping and save maintenance dollars by switching from the effluent pumps to the BJM Pumps. They decided to ‘do a complete change-out’, replacing the effluent pumps with the XP-SKX150CSS, which is rated for 550gpm @ 80ft of head.
After 9 months of uninterrupted service, two additional XP-SKX150CSS Explosion-Proof Submersible Shredder Pumps were installed in April 2017 into the manufacturer’s wastewater sump. Tencarva worked with BJM Pumps to design a custom adaptor plate, which was then manufactured by Tencarva and used to install the BJM Pumps onto the existing guide rail system. Two of the XP-SKX pumps will operate continuously to keep up with the 24/7 inflow, and operation will rotate between all three pumps in order to further extend pump life.
With a 6-inch pump connection being reduced to a 3-inch flanged slide rail connection, the XP-SKX pumps are now sending all the shredded material through the discharge pipe. Some of the particulate is being collected in a strainer and sent out for proper disposal. “They haven’t had any problems with the first XP-SKX pump that was put in,” declares Stolt, “and we’re looking forward to seeing how long the BJM Pump’s will run before needing to be pulled for repair.”
Do the Math! Selecting the Right Pump Saves Money!
This manufacturer spent about $180,000 by purchasing the effluent pumps and approximately $100,000 in a year repairing pumps that were just not right for their specific application. By switching to BJM Pumps, this manufacturer has saved money through reliable operation and reduced maintenance.
The manufacturer’s maintenance manager quips, “Even if we just get 1 year out of these BJM pumps and throw them away, we are winning. The BJM pump had a 2 month payback!” Doing that math should open your eyes to the importance of selecting the right pump for your specific application.
Learn more-> XP-SKX Product Page