Heavy Duty Balanced Opposed Compressors - Ariel Corporation

For Models: JGH:E:K:T Section 3 - Maintenance
each side. Paper against the bore surface not stained through may indicate under-lubrication;
both papers stained through may indicate over-lubrication. In either case, Ariel normally recommends
changing lubrication rate accordingly and repeating all paper tests until passed.
4. Repeat this procedure for all cylinders. If the test indicates a lubrication rate reduction or increase
for a cylinder, change in 5% increments by adjusting cycle time at the force feed lube pump (see
“Force Feed Lubricator Adjustment” on page 3-15). Repeat oil film testing, for affected cylinders,
after 24 hours of operation.
NOTE: The paper test indicates only oil film quantity. Aftermarket devices exist that measure
flow. Neither method indicates viscosity quality. Oils diluted with water, hydrocarbons, or
other constituents may ostensibly produce an adequate film or flow, but dilution may reduce
load-carrying capability below requirements.
Under/Over Lube
Under lubrication causes extremely rapid breakdown of piston and packing ring materials. Black,
gummy deposits in the distance piece, packing case, cylinder, and valves indicate under lubrication.
When symptoms indicate under lubrication:
• Verify proper operation of force feed lubricator pumps.
• Confirm distribution block cycle time matches the lube sheet or force feed lubricator data plate.
• Verify all tubing and fitting tightness; check for leakage. Check fittings inside cylinder gas passages.
• Pressure test or replace divider valves to ensure they do not bypass.
Over lubrication can result in excessive oil carryover into the gas stream, and increased valve and
gas passage deposits. Valve plate breakage and packing failure may also indicate over-lubrication.
Lubricator Cycle Time
Lubricant flow rates (measured in seconds per cycle) are generally so low that all required flow to a
lube point may consist of a drip at a loosened supply fitting. Ariel calculates break-in and normal lube
rates (cycle times) stamped on the force feed lubricator data plate to match gas and operating
conditions supplied with the compressor order. The lube sheets in the Ariel Parts Book state gas
conditions and list the base rate multiplier at each lube point. If gas conditions were not supplied with
the compressor order, the data plate/lube sheet rates apply to clean, dry, 0.65 specific gravity, sweet
gas at frame rated speed and discharge pressures.
Changes in operating conditions (such as gas properties or pressures, temperatures, flow
requirements, or cylinder re-configuration) require lubrication rate re-calculation and possibly force
feed lubrication system alteration. Consult your Packager and/or Ariel.
To set proper force feed lubricator pump flow rate, read the cycle time on the Proflo electronic
lubricator fluid-flow monitor/no-flow timer switch located at the distribution block or in the control
panel. For a digital no-flow timer switch (DNFT), time the cycle from flash to flash; for a magnetic
cycle indicator assembly, time the cycle from initial indicator pin movement at the fully retracted
position to the time when the pin returns to the fully retracted position and just begins initial
movement out again. Adjust the lubricator pump to provide the required cycle time.
NOTE: Do not set the force feed lubrication pump stroke too low. Pump output can become
inconsistent when set too low.
Break-in Rate
Set the break-in cycle time about half the normal cycle time (67% max.) to increase lube rate.
Maintain this break-in rate for 200 hours of operation for new equipment, or when replacing packing
and/or piston rings. Contact Ariel if existing pump is incapable of minimum flow rate required.
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