GE 7FA.05 - Lube Oil System Maintenance; Lube System Oil Pumps; Lube Oil Tank; Lube Oil Properties

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Inspection and Maintenance Instructions for 7FA.05 Gas Onl

and Dual Fuel Gas Turbine

GEK 116862

IX. LUBE OIL SYSTEM MAINTENANCE

A. Lube System Oil Pumps

Check the lube oil pumps for excessive vibration. Check the thrust bearings and bearing seal for

wear. Check the clearance of the wear ring per the manufacturer’s maintenance manual.

B. Lube Oil Tank

Check the internal tubing and piping of the lube oil tank for peeling of paint and loose fittings. Check

the pipe hangers for loose or missing hardware. Carefully inspect each pump intake screen (especially

on the main pump) for foreign material and loose hardware. Check the sludge removed from the

bottom of the tank for the presence of unusual material. Make sure the inside of the tank is

thoroughly clean before refilling.

C. Lube Oil Properties

For instructions on determining lube oil physical properties and periodic sampling and testing, refer

to the Fluid Specifications section of the Operation and Maintenance Manual.

D. Heat Exchangers

Check the heat exchanger for leakage, efficient operation and foreign matter contamination.

Exchangers are subject to fouling (scale, sludge deposits, etc.) and should be cleaned periodically,

depending on site specific cooling water and lube oil conditions. A light sludge, or scale coating, on

either side of the plate greatly reduces its effectiveness. A marked increase in pressure drop and/or

reduction in performance usually indicates cleaning is necessary. Since the difficulty of cleaning

increases rapidly as the scale thickens or deposits increase, the intervals between cleanings should not

be excessive.

To clean or inspect the inside of the plates, remove only the necessary inspection covers and

tightening bolts.

If an exchanger gasket should develop a leak, all gaskets shall be inspected and replaced as necessary

per the manufacturer’s maintenance manual.

E. Lube Oil Immersion Heaters

These steel sheath heaters are designed for non-circulating oil application. The heaters have to be

fully immersed in a liquid while energized.

F. Mist Eliminator

The pressure drop across the unit should be checked at startup and periodically during operation.

Refer to the lube oil system schematic piping diagram. A high pressure drop could indicate, (1) the

mist eliminator elements are plugging with solids, or (2) the oil vapor flow rate is too high. A low

pressure drop could indicate bypassing of some sort, particularly if smoke is visible.

G. Mist Eliminator Fan

Periodically check the fan wheel and housing for cleanliness. If there is excessive vibration, or high

bearing temperature, it may indicate motor bearing wear, blade wear, or a build up of dirt. Also check

the tightness of the mounting bolts and set screws. (See Standard Maintenance Items in this section

for motor inspection.)