L/O Flush

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THIS HAS BEEN AWARDED EMERGENT SOLE SOURCE

24100_TAB_0325_754

1. ITEM 1: Main Reduction Gear and Cross Connect Gear Hydraulic System, Flush

1. SCOPE

1.1 Intent. This work item describes the requirements for the Contractor to perform a high turbulent oil flush of the Port and Starboard Main Reduction Gear (MRG) and Cross-Connect Gear (CCG) Reduction gears.

1.2 Government-furnished property.

None.

2. REFERENCES

Coast Guard Drawings

Coast Guard Drawing 750-WMSL 100-83, Rev A, Booklet of General Plans (NSC 5 and follow) (ASC801001) (UNSIGNED)

Coast Guard Publications

Surface Forces Logistics Center Standard Specification 0000 (SFLC Std Spec 0000), 2022, General Requirements

Surface Forces Logistics Center Standard Specification 5000 (SFLC Std Spec 5000), 2022, Auxiliary Machine Systems

Coast Guard Technical Publication (TP) 7073, SWBS 241, Jun 2007, Reduction Gear -Type AS 2/250-AS 198F –book 1, parts 1 thru 8

Other References

International Organization for Standardization (ISO) 4406, 1999, Hydraulic Fluid Power – Fluids – Method for Coding the Level of Contamination by Solid Particles

3. REQUIREMENTS

3.1 General.

3.1.1 CIR.

None.

3.1.2 Tech Rep.

Not Applicable.

3.1.3 Protective measures. The Contractor must furnish and install all protective measures in accordance with SFLC Std Spec 0000, paragraph 3.3.3 (Vessel component, space, and equipment protection).

3.1.3.1 Hydraulic system. The Contractor must maintain existing hydraulic system cleanliness and take all necessary precautions to prevent the introduction of contaminants into the hydraulic system. Immediately after disconnecting or removing components from the hydraulic system, the Contractor must completely seal all openings to the rest of the system using caps for externally threaded connection points, bolt-on blanks, or taped-on discs/covers made of durable plastic or sheet-metal that is no less than 1/16-inch thick.

NOTE

Plastic bags may be used only when arrangement or configuration prevents the use of the other sealing methods specified above.

3.1.4 Interferences. The Contractor must handle all interferences in accordance with SFLC Std Spec 0000, paragraph 3.3.5 (Interferences).

3.2 System flushing. The Contractor must flush the subject hydraulic system in accordance with paragraph C2.8.1 of SFLC Std Spec 5000. Submit a detailed flushing plan in accordance with paragraph C2.8.1.1 of SFLC Std Spec 5000 via a CFR.

3.2.1 Contractor must ensure the following Table 1 minimum flow rates are maintained for each circuit. If multiple loops are flushed concurrently each loop must be provided with a flow measuring device. These flow rates represent minimum flows needed to achieve a turbulent flow condition and maximize benefits of flushing effort. The Contractor must provide calibrated flow meters. Prior to flushing the certification of calibration must be shown to the CG Inspector.

TABLE 1 - MINIMUM FLOW RATE FOR FLUSHING WITH FLUID

Pipe Size inside dia, Inch

Gal/Min

To 0.5

18

0.5 to 0.75

34

0.75 to 1.0

56

1.0 to 1.25

100

1.25 to 1.5

138

1.5 to 2.0

230

2.0 to 2.5

330

2.5 to 3.0

420

NOTE

Flow rate selected for flow velocity of 25 ft/sec in the schedule 80/160 pipe, as applicable. If there is a conflict between the pressure and flow rate requirements of this specification, the minimum flow rates must be governing, unless the working pressure of the system is exceeded. The uses of by-pass (flow control) valves are not allowed downstream of the flow meters.

3.2.2 Whenever a noticeable increase in the pressure drop across strainers is observed, the strainers should be cleaned and bag renewed. Be aware that this may occur as frequency as 15 min intervals.

3.2.3 During flushing, constant monitoring of the flushing oil must be maintained to determine the contamination level. Filtering must continue until the fluid entering the return flow filter meets the particle population ISO cleanliness code of 17/14, in accordance with ISO 4406. All flushing fluid must pass through the return filter after passing through each system flushing circuit. All samples must be taken at a point just prior to this filter.

3.2.4 Take a representative sample of oil from the hydraulic system of the hydraulic system. Send samples out for laboratory analysis. Analysis must include viscosity, moisture content, total acid number, particle size and population in sufficient detail to determine ISO cleanliness code of 17/14, in accordance with ISO 4406. Submit CFR.

4. NOTES

This section is not applicable to this work item.

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