Many municipalities and highway agencies use magnesium chloride solutions for deicing roads in the winter. One Colorado municipality contacted DXP Quadna when the pumps that transferred their salt solution into and out of their storage tanks frequently required repair because of mechanical seal failures. The costs were adding up.
Determining the Cause of Mechanical Seal Failure
DXP Quadna’s technicians thoroughly examined the failed seals. They discovered the most common reason for seal failure was salt deposits building up on the atmospheric side of the seal. This caused the dynamic O-ring to hang up, preventing the faces from running in contact with one another.
Solution One: Metal Bellows Seals
The first solution was to replace the standard mechanical seals with a metal bellows-style seal from Flexaseal, a longtime innovative DXP partner. The Flexaseal offering actually cost less than the previous O-ring-style seals, and the metal bellows design eliminated the dynamic O-ring that resulted in seal failure. The metal bellows seals eliminated the failures due to salt buildup but were still failing more frequently than expected.
Further inspection revealed the seals were occasionally running dry, which caused the silicon carbide faces to shatter. Several pump operators were letting the equipment run, even after the supply trucks were empty. The lack of lubricating fluid between the seal faces when the pump was running empty caused heat buildup and face failure.
Solution Two: High-Quality Packing
The DXP Quadna representative leading this project asked the facility manager if they would be willing to put up with a slow drip from their pump. The dripping fluid could easily be contained secondarily, and the sealing solution would be much more reliable, not relying on the truck drivers to operate the pumps carefully. The facility wanted to try this approach. We changed the pump’s seal cover plate from a tapered bore to a conventional stuffing box. In addition, we provided high-quality packing that the client would be able to to maintain and replace themselves without having to disassemble the pumps. This reduces service time and eliminates waiting for replacement seals to arrive. They previously replaced seals so often that it was hard to keep enough backups on hand.
With this new packing setup, the periodic dry running does not result in failing seals, spilled product, or extended downtime for repairs. The operators can easily perform simple maintenance and repairs on their own. The packing is also much less expensive than mechanical seals that had to be replaced constantly. Mechanical seals are incredible devices and generally the better option for many pump applications. However, in this case, applying the old KISS principle (“keep it simple, stupid”) was the right call.
Another Satisfied Customer
DXP Quadna keeps this client stocked with high-quality packing, though they only have to reorder every couple years. We do not replace their mechanical seals often or provide emergency pump repair services anymore, so we lost some business. Ultimately, our priority is to make sure our customers have the best pump solutions for long-term performance and reliability. We are committed to resolving issues, rather than just wanting to sell more parts.
If you are looking for more reliable solutions for your unique pump challenges, contact the experts at DXP Quadna today.
