Heavy Duty Balanced Opposed Compressors

FOR MODELS: JG AND JGA SECTION 5 - MAINTENANCE
equally spaced. This prevents the stack of parts from being aligned incorrectly.
Remove the stud nuts and the pressure packing can be un-stacked. Replace
these nuts each time the pressure packing is serviced.
7. Ring wear can be determined by placing the assembled rings, (note matchmarks),
on the piston rod. Check end gap clearance. If the ends butt, or nearly
butt, they should be replaced by new rings.
8. Fins or wire edges on the rings due to wear should be carefully filed off so that
all matching edges will be square.
9. The metal gasket on the end cup can be pried loose with a sharp awl. Be careful
not to scratch the sides of the gasket groove.
10. Before reassembly be certain all parts are perfectly clean.
Piston Rod Packing - Reassembly
1. Be sure to refer to the pressure packing assembly in your parts book. Please
contact your distributor if you do not have a parts book. A pressure packing
assembly drawing also is packaged with each pressure packing re-build kit.
2. If installing a new set of rod rings in an existing packing case, the case parts
need to be inspected for wear. Cups should be smooth and flat on the back side
where the rod rings must seal. If the cups or grooves have worn concave or
tapered, they should be reground or relapped. It is rarely necessary to alter the
crosshead side of the cups, however, if this is found necessary, care must be
taken so that the correct side clearance for the renewal rings is not destroyed.
NOTE: IF PREMATURE WEAR IS SUSPECTED, REFER TO THE ARIEL See “Cylinder
And Packing Lubrication Requirements” on page 4-5.
3. Before a packing case is installed, it should always be disassembled and thoroughly
cleaned in an appropriate solvent for the intended service.
4. Make sure that each rod ring and cup is properly positioned and that rings are
liberally coated with a clean lubricant before reassembly. Examine all parts for
unusual nicks or burrs which might interfere with the free floating of the rod ring
in the cups. Particular care should be taken with rod rings made of soft materials,
such as bronze or TFE, and it is extremely important that wiper rings be
handled and installed so as to prevent damage to the scraping edges.
5. Parts should be laid out on a work bench so that they can be installed progressively
with each in its correct position and the rod rings with their proper faces
toward the pressure. Note that all rod ring segments are carefully lettered and
must be assembled accordingly. This is most important in order to ensure
proper sealing. After the tie stud nuts are tightened, all rings should be free to
“float” radially in each cup.
6. For new installations, care must be given to the cleaning of all accumulated dirt
in the lines and compressor because foreign material will lodge in the packing to
become destructively abrasive.
7. Prior to installing the packing case into the cylinder, the end cup gasket must be
inspected for nicks and damage that would cause it to leak in service. When in
doubt, replace the gasket with a new one.
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