Heavy Duty Balanced Opposed Compressors - Ariel Corporation

Section 3 - Maintenance For Models: JGH:E:K:T
NOTE: Ariel recommends not disturbing lube oil piping downstream of the oil filter. Contaminants
that enter that piping or open ports are flushed into the bearings causing catastrophic
damage. To remove or alter piping, cover the oil gallery inlets, the piping ends, and the filter
outlet so no contaminants enter. Before reinstallation, chemical and mechanical cleaning is
required. Then flush the pipe in accordance with Ariel cleanliness requirements (Table 3-2).
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.
1. Prior to assembling lube oil piping, remove scale, weld slag, rust and any other matter that could
contaminate lube oil. Confirm:
• Complete and closed lube oil system.
• Crankcase or sump 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 bar g ) for effective flushing. Do not exceed 90 psig (6.2 bar g ).
3. Flush continuously for one 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 one 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 one continuous hour of flushing within differential
pressure and temperature increase limits.
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 3-2), prior to start-up.
See ISO-4406 "International Standard -
Hydraulic fluid power - Fluids - Method for
coding level of contamination by solid
particles" and/or NAS-1638 "National
Aerospace Standard, Aerospace
Industries Association of America, Inc. -
Cleanliness Requirements for Parts Used
in Hydraulic Systems" for complete
information. Use a competent oil lab for
sample testing.
TABLE 3-2 Oil Flushing Cleanliness Requirements
Grade
Requirements
ISO-4406 Grade 13/10/9
Particle Size
µm/mL Oil Sample
Number Particles
Allowed
/13 Greater than 4 40 to 80
/10 Greater than 6 5 to 10
/9 Greater than 14
NAS-1638 Grade 5
2.5 to 5
Particle Size Range
Grade 5
µm/100mL Oil Sample Maximum Number Particles
5 to 15 8,000
15 to 25 1,424
25 to 50 253
50 to 100 45
Over 100 8
Force Feed Lubrication System Components
In the force feed lubrication system, oil flows to the force feed lubricator pump inlet(s) from the frame
lubrication system, or from an overhead tank. Next in the discharge lines are blow-out (rupture)
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