Page 204 - Reciprocating Compressors Operation Maintenance

1 9O Reciprocating Compressors: Operation and Maintenance

Reconditioning should be done by a qualified service shop, preferably
one of the packing manufacturers that specializes in packing case
rebuilding.
The best general practice suggests having available a spare set of
packing that has been reconditioned by the packing manufacturer. The set
that is removed at the next overhaul should be reconditioned by a compe-
tent repair facility prior to being returned to stores.
Whenever the packing is opened for inspection, the end clearance of
the rings should be checked and the original clearances restored, if neces-
sary. This adjustment is made by filing an equal amount off the end of
each segment. Do not remove all the material from one segment.
Table 3-10 gives typical end clearances for various styles of rings and
different rod diameters.

TABLE 3-to
PACKING RING END CLEARANCE AT EACH CUT
(REPAIRS ONLY)

Ring Type Rod Diameter, Inches
(See Figure 3-50) 2 3 4 6
a,b,c M 6" &" %" %f
d, e, f 34" %2"
g .004" .006" .008" .012"
h No End Clearance
j 34" 34" 3 /n' { A"

It is a far better maintenance practice to install new rings and springs
than to rework the old rings. The cost of these parts is small in compari-
son to compressor shutdowns caused by packing failures.

SERVICING PRESSURE PACKING

When cleaning packing rings, wire edges may be found around the
bore of the rings if considerable wear has occurred. These wire edges
must be removed with a file. However, care should be taken to not break
the corners where any two surfaces of a packing ring match.
If packings are to be paired with old rods, check the rod for size and
trueness. If scores or shoulders are present, the rod should be refmished
or replaced. All scores and abrasions should be removed by stoning.