TCO: PetrochemicalMegan Thompson
Motor Type: AC Vertical
Manufacturer: US Electric
Refineries and chemical plants are full of vertical motors, driving pumps which supply hydrocarbons or hazardous organic chemicals. When mated to the pump, vertical motors that are not machined and assembled to handle high tolerances will induce mechanical stresses and vibrations on pump bearings and seals. This can result in hydrocarbon or chemical leakage, causing spills, fires, explosions and injury to plant workers. It can also mean involvement from the Environmental Protection Agency (EPA), as plants are responsible for reporting all leaks and spills to the agency.
IPS machinists have developed proprietary tooling and extensive procedures to achieve the highest machining tolerances when reconditioning or rewinding vertical motors, in particular, paying close attention to the shaft run-out of a vertical motor to the motor base spigot (rabbet). These superior tolerances deliver reliability and longer life to the pump seals and bearings and include the following:
• 0.001” shaft run-out. Typical shaft run-out of new or repaired motors is 0.002” to 0.005.”
• 0.001” flange face run-out. Typical face run-out of new or repaired motors is 0.003” to 0.015.”
• 0.001” rabbet fit run-out. Typical rabbet fit run-out of new or repaired motors is 0.003” to 0.015.”
• Maintain rabbet opening to 0.004” of standard.
Even though the IPS premium machining process takes more time and is more expensive when compared to less stringent machining processes, the refinery experienced $12,400 in annual savings per motor, or over $60,000 in total savings per motor over the past 5 years, since receiving the updated IPS vertical motor machining. These savings are driven by the following:
• Reduced frequency in reconditions – from 6 to 9 months in service up to 2 to 3 years in service.
• Reduced EPA reporting – giving the plant a better score with the EPA and saving time for plant staff
Download the complete case study and calculations below: