Heavy Duty Balanced Opposed Compressors - Ariel Corporation

For Models: JGH:E:K:T Section 3 - Maintenance
The compressor requires a 45 psig (3.1 barg ) low oil pressure shutdown for protection. Do not
operate the compressor for prolonged periods at less than 50 psig (3.4 barg ) oil pressure.
For proper operation of the thermostatic control valve, the maximum differential pressure between
the hot oil supply line and the cooled oil return line is 10 psid (0.7 bard ).
Frame Oil Temperature
To drive off water vapor, the minimum lube oil operating temperature is 150°F (66°C). Maximum
allowable oil temperature into the compressor frame is 190°F (88°C).
Ariel offers a thermostatic control valve set at 170°F (77°C). Maintain oil temperature as close to this
temperature as possible. Higher temperatures increase the oxidation rate of oil. Every 18°F (10°C)
over 150°F (66°C) doubles the oxidation rate of oil.
Frame Oil Maintenance
Change compressor frame lubricating oil as indicated in the regular maintenance intervals or with a
filter change or when oil analysis indicates the need. Some compressors may require more frequent
oil changes if operating in an extremely dirty environment without sampling and analysis or if the oil
supplier recommends it.
Frame Oil Sampling
Typically, packagers install an oil sampling point between the oil pump and filter at an easily
accessible location. Collect and analyze oil samples to verify suitability for continued service.
Consistent oil analysis can identify when to change oil on the basis of need rather than a scheduled
interval. Depending on service, oil analysis can significantly extend oil change intervals. Oil analysis
should include:
• Viscosity testing at 100°F (40°C) and 212°F (100°C). Determines whether cylinder oils or process
gas diluted the oil.
• Particle counting to the latest version of ISO 4406.
• Spectroscopy to determine wear metals, contaminants, and additives.
• FTIR (Fourier Transform Infrared Spectroscopy) to check for oxidation, water or coolant contamination,
and additive depletion. This is more important if a force feed system uses separate lube oil.
Dry Sump
Compressors subject to transient motion, roll, and yaw on board a ship or floating platform may
require a dry crankcase with a separate oil reservoir. With a dry sump, Ariel provides drains at each
end of the compressor frame and an oil pump chain oiler. The packager provides a lube oil reservoir
sized and located to provide oil suction to the oil pump regardless of tilt. There should be a 30 mesh
(595 microns) oil sump strainer in the pump suction line at the lube oil reservoir outlet. Remove
strainer basket and wash it in an appropriate solvent whenever lubricating oil is changed.
Oil System Cleanliness
Clean compressor frame oil piping system and components of all foreign matter such as sand, rust,
mill scale, metal chips, weld spatter, grease, and paint. Ariel recommends using a commercial pipe
cleaning service to clean the oil piping system. If not practical, use proper cleaning procedures with
proper cleaners, acids, and/or mechanical cleaning to meet cleanliness requirements. Dispose of
cleaning by-products properly; a disposal service is recommended. Ariel also 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.
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