Heavy Duty Balanced Opposed Compressors - Ariel Corporation

FOR MODELS: JGZ AND JGU SECTION 4 LUBRICATION
let. Measures which may be necessary to make sure that the force feed pump is filled with oil
during the suction stroke include; appropriate pipe and fitting size from the tank to the force
feed pump, heating the oil, and pressurizing the supply tank. An in-line oil filter or fine screen
is required between the supply tank and the force feed lubricator pumps. Recommended filtration
is 5 micron nominal.
Gas Inlet Debris Screens to Maintain Lube Performance
Even when the proper rate and lubricating medium are in use, dirt and foreign matter in the
gas will prevent the lubricant from performing properly. Prior to start-up, cone type inlet gas
debris strainers with 100 mesh per inch (150 micron) screen and perforated metallic backing
are to be installed in a pipe spool between the inlet scrubber and cylinder suction flange. In
order to protect the compressor cylinder, any piping or vessels downstream of the screen
must be thoroughly cleaned to be sure that no debris is present. Proper maintenance of the
inlet screens is required. Inlet debris strainers should be monitored by differential pressure
and cleaned before the differential pressure approaches the collapse pressure of the screens.
High differential pressure alarm/shutdown switches can be used to protect against screen collapse.
Injection Oil Inlet Filter
An in-line oil filter or fine screen is required between the oil supply or supply tank and the force
feed lubricator pumps. Ariel recommended filtration is 5 micron nominal. The compressor filtration
system is adequate for systems that use frame lube oil for the force-feed cylinder and packing
injection. For separate force-feed lube oil supplies, a filter must be installed by the
packager.
Oil Dilution
Cylinder lubrication requirements will vary with the operating conditions and the composition
of the gas to be compressed. Careful consideration must be given to proper cylinder lubrication
selection. The degree of cylinder oil lubrication dilution/saturation by the process gas
stream is influenced by the following factors:
1. Process gas composition/Specific Gravity (SG) - usually the higher the SG, the
greater the oil dilution.
2. Discharge gas pressure - the higher the pressure, the greater the oil dilution.
3. Discharge gas temperature - the higher the cylinder discharge temperature, the
less the oil dilution.
4. Lubricant selection - some types of oil are more prone to dilution than others.
Cylinder Oil Lubrication Examples
Refer to Table 4-6 for lubrication recommendations for various gas compositions and various
operating conditions. Note that lubrication rates can change with operating conditions. Lubricating
oil type will also vary with the composition of the gas which is to be compressed.
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