Line shaft bearings and stationary wear rings made from DuPont Vespel CR-6100 material were retrofitted into pumps to prevent failure during run-dry conditions at an oil refinery.
Run-dry conditions were causing failure of line shaft bearings and stationary wear rings in two vertical pumps for hot well condensate (water) at a major oil refinery. The process temperature at the refinery is 82ºC.
Thermoplastics tried as a solution failed because their high coefficient of thermal expansion caused the line shaft bearings to grow into the shaft, causing the parts to be destroyed when the pump ran dry. Seizing was the most common failure mode.
The pumps were then retrofitted with DuPont Vespel CR-6100 parts for line shaft bearings and stationary wear rings.
To demonstrate the efficacy of Vespel CR-6100 in surviving the conditions at the refinery, site personnel installed a retrofitted pump and performed a field test. The suction valve was closed and amps were monitored to verify that the pump was not seizing.
After 30 minutes with suction pressure showing 18 inches of vacuum, the ammeter reading did not change, and there was no damage to the bearings or wear rings.
In over four years of service, no seizure failures have been reported in the line shaft bearings or wear rings proving their exceptional reliability.
Due to its success in the condensate return pumps and subsequent applications at the refinery, Vespel CR-6100 has become a standard material for stationary wear rings and line shaft bearings. The material has been successfully applied to hundreds of the refinery’s pumps.
Key benefits of DuPont Vespel CR-6100:
- Survives run-dry conditions in pumps
- Material runs with reduced clearances and survives in the process for extended periods of time
- Low coefficient of thermal expansion
- Low coefficient of friction
- High PV capacity
- Low wear rate
- Low water absorption
DuPont Vespel CR-6100 is available from Fluid Seals .