Power lubricants

Where a power plant uses oil and grease

• Steam and gas turbine bearing and governor systems
• Generators and turbine auxiliary gearboxes
• Boiler feed pumps, fans and mills
• Hydraulic systems for control and valves
• Air compressors for instrument and plant air
• Motor and fan bearings throughout the plant

Turbine oil

Turbine oil circulates for a long time through bearings and control systems, so it has to resist oxidation, release water and air quickly, and protect against rust and foaming. Common grades are ISO VG 32 and 46, but follow the turbine maker's specification. Test the oil on a schedule for water, acidity and particles, and keep the system clean.

Gear oil for auxiliary gearboxes

Gearboxes on pumps, fans and mills usually take an extreme-pressure (EP) gear oil of the grade the gearbox maker gives. Heavily loaded or hot gearboxes may call for a synthetic EP oil for long drain intervals. Watch the oil temperature and keep water out.

Hydraulic oil for control systems

Control and valve hydraulics need an anti-wear (AW) oil in the grade the equipment maker specifies, often ISO VG 32, 46 or 68. Clean oil is vital. Dirt and water shorten the life of valves and pumps.

Compressor oil for plant and instrument air

Screw and reciprocating compressors need a compressor oil that resists oxidation and carbon build-up. Clean, dry air supports instruments and controls, so keep to the oil-change and filter schedule.

Grease for motors, fans and bearings

Motor and fan bearings run for long periods, often warm. A lithium complex grease of the right consistency, often NLGI 2, suits many of them. Do not over-grease, because that also makes bearings hot. Use a fixed greasing plan.

How to choose the right lubricant

• Start with the equipment maker's manual.
• Note the temperature, load and running hours.
• Match the viscosity grade and the performance level (turbine, AW, EP).
• Ask for a sample and test it on one machine first.
• Set an oil-testing and change plan, and keep to it.