Heavy Duty Balanced Opposed Compressors - Ariel Corporation

Section 3 - Maintenance For Models: JGH:E:K:T
Oil Cooler
The oil cooler maintains oil temperature in the compressor frame below the maximum limit. In sizing
a proper oil cooler, the packager considers the cooling medium and its temperature and flow rate,
and the lube oil temperature and flow rate. The Ariel Performance Program lists oil heat rejection
data for each frame in the frame details section (contact your packager or Ariel for details). It also
lists required cooling water flow rate and temperature to properly cool oil with Ariel supplied coolers.
Insufficient cooling water flow rate is the primary cause of high oil temperatures.
Mount the cooler as close to the compressor as possible with piping of adequate size to minimize
pressure drop of both lubricating oil and cooling medium.
Oil Temperature Control Valve
The cooler requires thermostatic valves
to control compressor oil temperature. A
thermostatic valve is a three-way valve
with a temperature sensitive element. As
the oil heats, the sensing element opens
the third port in the valve.
Two configurations determine
thermostatic valve operation: diverting
mode and mixing mode. In diverting
mode, the oil diverts to the cooler when
compressor oil is hot enough to open the
valve. In mixing mode, the element opens
a port in the thermostatic valve that
Lube Oil
from Main
Oil Pump
Lube Oil Cooler
Lube Oil
to Main
Oil Filter
Thermostatic
Control Valve
Thermostatic control valve configuration may vary from this schematic,
depending on valve size. Valve connections A-B-C are
marked on the valve.
FIGURE 3-2 Lube Oil Thermostatic Valve in Mixing Mode
allows oil from the cooler to mix with hot oil from the bypass. Diverting mode monitors temperature of
oil from the compressor. Mixing mode monitors temperature of oil to the compressor. Ariel
recommends mixing mode configuration.
Frame Oil System Components
Oil Strainer
An oil strainer installed upstream of the pump prevents debris from entering the pump and damaging
it. Ariel supplies a 30 mesh (595 microns) strainer on all JGH:E:K:T compressors. It is located on the
auxiliary end of the crankcase below oil level. Remove the strainer basket and wash it in an
appropriate solvent whenever lubricating oil is changed. For dry sump frames, the lube oil strainer
ships uninstalled from the factory. The packager installs it in the piping later.
Oil Filter
All compressor frames require oil filters to remove contamination that can damage both equipment
and oil. Contaminants that damage equipment include:
• Wear particles from equipment • Solid particles from gas stream
• Airborne particles such as dust or sand • Dirt from new refinery oil
Contaminants that damage oil include soot (commonly from engine combustion), oxidized oil
components, and air bubbles.
Ariel JGH:E:K:T frames ship with simplex, spin-on resin-impregnated filters as standard. Spin-on
filters have a 5 micron nominal and 17 micron absolute rating. The Beta ratings are ß5 = 2 and ß17 =
75. Many spin-on filters fit an Ariel compressor, but very few meet filtration ratings of Ariel filters. For
this reason, Ariel recommends no after-market filters. Exercise caution if using an after-market filter.
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A
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