Heavy Duty Balanced Opposed Compressors - Ariel Corporation

FOR MODELS: JGZ AND JGU SECTION 4 LUBRICATION
Under/Over Lube
Inadequate - (under) lubrication. This condition results in extremely rapid breakdown of piston
and packing ring materials. Black, 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 may also be symptoms of over lubrication.
Inadequate Lubrication Symptoms
When observed symptoms indicate inadequate 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. Pressure test or replace divider valves to be sure they are not bypassing.
Lubrication Quantity - Paper Test Method
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 the head
end head and position piston at about inner center, for the cylinder to be checked. “Lock out”
so that crankshaft can not be accidentally turned; see the “CAUTION” in Technical Manual
Section 5 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” in Technical Manual Section 3. 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. AFTERMARKET DEVICES THAT MEASURE FLOW ARE ALSO
AVAILABLE. NEITHER METHOD GIVES AN INDICATION OF VISCOSITY QUAL-
ITY. OILS DILUTED WITH WATER, HYDROCARBONS OR OTHER CONSTITU-
ENTS MAY PRODUCE WHAT APPEARS TO BE AN ADEQUATE FILM OR FLOW.
BUT THE OIL FILM MAY NOT HAVE THE REQUIRED LOAD-CARRYING CAPA-
BILITY DUE TO THE DILUTION.
Lubricator Cycle Time
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 loosened supply fitting. The
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