Lm2500 Flush

Off Engine Lube Oil System Cleanliness - Gas Generator

Investigation into determining sources of gas generator bearing contamination which results in shortened lives, has led to the following standardized recommendations with respect to the off-engine lube system maintenance, flushing and cleanliness. These recommendations are applicable to both new and repaired engine testing and also for engine change outs in the field.

Operation and Maintenance Practices

1. Following component failure (lube/scavenge pump, VG control, starter, gearbox, bearings, etc.) filters must be changed, oil tank cleaned and a recirculation flush accomplished. Oil samples are required to substantiate system cleanliness.

2. Lube oil tank fill system must be clean. Contaminated lube oil and/or lube oil fill system will introduce foreign material into the lube system.

3. Installation and removal of the engine requires the opening of many lines and exposing bearings to potential contamination. All lube system connections must be covered immediately after disconnection.

4. Gas turbine pressurization system pulls air from both the engine compartment and the engine inlet in order to pressurize the bearing sump seals. There is, therefore, significant risk in operation with compartment doors open. Additionally, improper compartment cleanup following maintenance can pass contaminaants into the sumps through this flow path. Do not operate the engine with doors open, and always clean up after maintenance.

Lube System Flushing Procedure

The following is an outline of recommended off-gas turbine oil system flushing procedure. This should be performed prior to connecting the off-gas turbine lube system to an engine, or at any time that particulate contamination is suspected. The procedure uses a flush pump and filter to clean particulate contaminates from the oil system prior to connecting it to the gas turbine.

1. Inspect the inside of the supply oil tank for contamination. Wipe all tank surfaces clean an then install the tank access cover.

2. Connect a flush cart to the lube system supply and return interface connections (see Figure 1 for a typical system). Each supply and return may be flushed separately or manifold arrangement can be used to flush all circuits simultaneously (include the VG and hydraulic pump circuits, if applicable). The flush cart should consist of a pump which can produce approximately 1.5 time normal system flow (i.e. 30 gpm) and a 3 - 6 micron cleanup filter.

3. Start flush pump pump and monitor system cleanliness. Oil should be sampled periodically. 4. Actual required flush time will vary depending on the initial system contamination level and the

actual system volume. It is expected that a minimum of 8 hours of continuous flushing will be required to clean up a typical system.

5. When an oil sample meets the cleanliness standards outlined in Table 1, the engine may be installed.

Figure 1. Lube System Flush Cart (Typical)

Page 1 of 3Lubrication

19/11/2005http://inside-aep.ps.ge.com/insideaep/aep/iad/engine_prod_delv/idms/common/09cleanoil...

Table 1. Oil System Acceptance Criteria (Cleanliness) Flush cleanliness acceptance criteria - Particle size limits:

RangeMicrons

NAS-1638Cleanliness Classification

Particle Count (Based on 100ML Sample Size)

(per NAS-1638)

5 - 15 8 64,000

15 - 25 7 5,700

25 - 50 7 1,012

50 - 100 7 180

>100 7 32

In addition to flushing, an oil change will be required if the following limits are exceeded.

H2O Limit: 1000ppm TAN Limit 1.0 KOH/gm Viscosity Limit: -10% to +25% ref to new oil SOAP Analysis: Either Atomic Absorption or Emission Method as indicated below.



SOAP Analysis Atomic Absorption Method Particle Quantity Ranges for Monitoring (in ppm)

Element Normal On Watch Shutdown

Iron (Fe) 0 - 3 4 - 7 8+

Silver (Ag) 0 - 1 2 - 4 5+

Aluminum (Al) 0 - 1 2 - 4 5+

Chromium (Cr) 0 - 4 5 - 7 8-

Copper (Cu) 0 - 5 6 - 10 11+

Magnesium (Mg) 0 - 1 2 - 4 5+

Nickel (Ni) 0 - 3 4 - 6 7+

Silicon (Si) 0 - 20 21 - 36 37+

Titanium (Ti) 0 - 3 4 - 6 7+

Molybdenum (Mo) 0 - 3 4 - 6 7+

Lead (Pb) 0 - 3 4 - 6 7+

Tin (Sn) 0 - 15 16 - 22 23+

SOAP Analysis Atomic Emission MethodParticle Quantity Ranges for Monitoring (in ppm)

Element Normal On Watch Shutdown

Iron (Fe) 0 - 8 9 - 13 14+

Silver (Ag) 0 - 3 4 - 6 7+

Aluminum (Al) 0 - 3 4 - 6 7+

Chromium (Cr) 0 - 6 7 - 9 10+

Copper (Cu) 0 - 12 13 - 19 20+

Magnesium (Mg) 0 - 6 7 - 9 10+

Nickel (Ni) 0 - 5 6 - 8 9+

Silicon (Si) 0 - 25 26 - 64 65+

Titanium (Ti) 0 - 5 6 - 8 9+

Molybdenum (Mo) 0 - 5 6 - 8 9+

Lead (Pb) 0 - 2 3 - 4 5+

Tin (Sn) 0 - 20 21 - 39 40+



Documents

Lm2500 Flush