The left-over tar and coke from the petroleum extraction process are pumped to holding tanks. Due to the design of Exxon’s system, it is possible for the pumps to run dry when not enough tar is present in the strainer. This causes major damage to the impeller and pump casing. There is a discharge valve to slow the pump output, but the valve sensor is frequently clogged with tar and does not work properly.
- Exxon needed to slow the pump speed down to prevent the pump from running dry. Maintenance personnel at the site were replacing the tar pumps up to 20 (!!) times per year.
- Exxon already had trouble with existing VFDs on other equipment, and so chose to install a MagnaDrive ASD on the tar pump
- Exxon has been able to turn the pump speed down to as little as 1100 RPM and has operated the tar pump with no problems whatsoever since the installation of the 12.5 rigid pedestal ASD.
- The pump has not been replaced at all, versus being replaced 12-20 times per year using only the discharge valve.
- Exxon also estimates that they save $15,000 per year in energy savings.