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Pump Maintenance

12.9. 1.2 Packing procedures
1. Ensure that all the old packing has been cleaned out of the
stuffing box, and clean the stuffing box and the sleeve
thoroughly. The sleeve should be replaced if any significant wear
is identified.
2. Measure the bore of the stuffing box and the diameter of the
shaft. Subtract the O.D. dimension from the I.D. dimension and
divide by 2. The result is the required size of the packing.
3. When using coil or spiral packing, always cut the packing to size.
Do not wind the packing into the stuffing box around the shaft.
When cutting the packing, always use a mandrel of the same size
as the shaft in the stuffing box.
4. Hold the packing lightly on the mandrel, but do not stretch it.
Cut all the rings in the same manner, either with a Butt Joint or
with a Skive Joint as shown.
Owing to the importance of
,
cutting the tings to the
correct size, Die-cut tings I I (
can be of great advantage as
they give you the exact size Butt Joint Skive Joint
ring for the I.D. of the box Figure 12.3: Cutting packing rings
and the O.D. of the shaft.
6. Install one ring at a time and make sure each ring stays clean prior
to installation.

7. Scat tings snugly against each other and the joints of successive
tings should be staggered and kept at least 90 ~ apart.
8. After the last ring is installed, take up the gland bolts finger tight
only. Do not jam the pacldng into place by excessive gland
loading.

9. Start pump, and allow the pacldng to leak freely on a new pump
or one that has just been overhauled. Excessive leakage during the
first hour of operation will result in more reliable packing
arrangement over a long period of time.
10. Gradually tighten up on the gland as the pacldng settles, until the
leakage is reduced to an acceptable level in accordance with plant
standards.
Note that all packing is permitted some slight amount of leakage in order
to provide cooling and lubrication between the packing and the sleeve.

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