Heavy Duty Balanced Opposed Compressors

FOR MODELS: JG AND JGA SECTION 4 - LUBRICATION AND VENTING
gummy deposits which can be found in the distance piece, packing case, cylinder and
valves are indicators of under lubrication.
Excessive (over) lubrication can result in excessive oil carryover into the gas stream, and
increased quantities of deposits in the valves and gas passages. Valve plate breakage and
packing failure are also symptoms of over lubrication. The packing case will “hydraulic”,
which forces the packing rings to lift off of the rod enough to form a leak path. Increased gas
leakage then results in packing and rod overheating. A rod and packing case can turn blue
even though the lubrication appears sufficient.
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. Inlet gas debris screens with a maximum
50 micron opening are recommended. Proper maintenance of the inlet screens is
required.
To check cylinders for the proper lubrication rates, the cigarette paper test method can provide
a practical indication. Relieve and vent all pressure from all cylinders. Remove a head
end suction valve and position piston at inner center, for the cylinder to be checked. “Lock
out” so that crankshaft can not be accidentally turned; see the “CAUTION” in “General Introduction”
on page 5-1 and refer to the Packager’s Operation Manual for details. Use two layers
of regular unwaxed commercial cigarette paper, together. Wipe the cylinder bore at top
with both papers using light pressure in circumferential motion through about 20°. The paper
next to the bore should be stained (wetted with oil), but the second paper should not be
soaked through.
Repeat the test at both sides of the bore at about 90° from the top, using two new clean
papers for each side. When the paper next to the bore is not stained through, it may be an
indication of under lubrication. When both papers are stained through, it may be an indication
of over lubrication. In either case, it is normally recommended that the lubrication rate
be changed accordingly and that all cigarette paper tests be repeated until passed. Repeat
for all cylinders. If a reduction or increase of the lubrication rate is indicated for a cylinder,
change in 5% increments by adjusting cycle time at the force feed lube pump as discussed
in “Force Feed Lubricator Adjustment” on page 3-8. Repeat oil film testing, for the cylinders
affected, after 24 hours of operation.
NOTE: THE CIGARETTE PAPER TEST ONLY GIVES AN INDICATION OF OIL FILM
QUANTITY. IT DOES NOT GIVE AN INDICATION OF VISCOSITY QUALITY.
OILS DILUTED WITH WATER, HYDROCARBONS OR OTHER CONSTITUENTS
MAY PRODUCE WHAT APPEARS TO BE AN ADEQUATE FILM. BUT THE OIL
FILM MAY NOT HAVE THE REQUIRED LOAD-CARRYING CAPABILITY DUE
TO THE DILUTION.
When observed symptoms indicate lack of lubrication; first verify that the force feed lubricator
pumps are operating properly. Confirm that the distribution block cycle time matches the
lube sheet or lubrication box information plate provided by Ariel, and double check that all
tubing and fittings are tight and no leaks are present. Do not overlook the fittings inside the
cylinder gas passages.
The lubricant flow rates (measured in seconds per cycle) are generally so low that all of the
required flow to a lube point may be observed as a drip at a fitting. The break-in and normal
lube timing rates which are stamped on the lubricator box information plate are calculated
according to the Ariel Lube Specifications to match the gas operation conditions as supplied
to Ariel with the compressor order. The lube sheets supplied in the Ariel Parts Book state
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