By Jim Fitch
Power Magazine
Lubricating oil is the lifeblood of virtually all rotating equipment found in a power plant. Keep it clean and the lube system is relatively low-maintenance. However, cycling operation and restarts after a temporary or long-term shutdown can create a whole new class of what may be unfamiliar problems. The fundamental question is determining when a lube oil flush is justified, and answering that question requires understanding the conditions that trigger the need for a flush. A good place to start is to consider the most common reasons a flush is required (see table). Often, the need to flush is first observed during an inspection, by the appearance of sludge in a sight glass, on a used filter, or at the bottom of a sump. This can be confirmed by oil analysis and further inspection. Remediation entails both the removal of the sludge, varnishing, or debris as well as removal of the root cause before the system can be returned to service.