Oil System Cleanliness

Clean the compressor frame oil piping system and components of all foreign matter such as sand, rust, mill scale, metal chips, weld spatter, grease, and paint. Use proper cleaning procedures with proper cleaners, acids, and/or mechanical cleaning to meet cleanliness requirements. Ariel recommends flushing all oil-piping systems with an electric or pneumatic driven pump and filtered, clean production oil. Ariel thoroughly cleans all compressor frame cavities prior to assembly and test runs compressors with a filtered closed loop lube system.

NOTE: Ariel recommends not disturbing lube oil piping downstream of the installed oil filter.

Contaminants that enter this piping or open ports flush into the bearings causing catastrophic

damage. To remove or alter piping, cover the inlets to the oil gallery, the ends of the

piping, and the filter outlet so no contaminants enter. Before reinstallation, chemical and

mechanical cleaning is required. Flush the pipe in accordance with Ariel cleanliness requirements

(see Table 6-3).

Prior to start-up, flush all compressors installed with an electric or pneumatic powered pre-lube pump and less than 50 feet (15 m) of oil piping as outlined below. Include cooler oil passages in the flushing loop. While oil systems for compressors without an electric or pneumatic powered pre-lube pump and less than 50 feet (15 m) of oil piping must be clean, oil flushing is desirable, but not required.

For all compressors with oil piping systems greater than 50 feet (15 m), cleaning and flushing must result in a cleanliness level to ISO-4406, Grade 13/10/9 and/or NAS-1638, Class 5 (see Table 6-3), prior to start-up.

1. Prior to assembling lube oil piping, remove scale, weld spatter, rust and any other matter that

could contaminate lube oil. Confirm:

• Complete and closed lube oil system.

• Crankcase filled to the correct level with appropriate oil.

• Proper and correctly installed lube oil filters.

• Operational and viewable oil pressure transducer or gauge, oil filter differential-pressure transducers

or gauges, and oil temperature RTD or indicator.

2. Start pre-lube pump. Record oil pressure, oil filter differential-pressure, and oil temperature. Minimum

oil pressure is 30 psig (2.1 barg) for effective flushing. Do not exceed 90 psig (6.2 barg).

3. Flush continuously for an hour. Oil filter differential-pressure must not increase more than 10% of

measured oil pressure into the filter. Record the oil pressure, oil filter differential pressure, and oil

temperature every 15 minutes. Oil temperature increases of more than 10°F (5.5°C) during an

hour of flushing invalidate the system cleanliness test, due to oil viscosity change.

4. After an hour of pre-lube flushing, if differential pressure or temperature increases exceed the

limits above, continue flushing. If the lube oil filter differential pressure exceeds change filter limits,

stop the pre-lube pump and change the oil filter. To ensure system cleanliness, re-set time

and continue flushing until the compressor achieves a continuous hour of flushing within differential

pressure and temperature increase limits.