Page 192 - Know and Understand Centrifugal Pumps

Pump Shaft Packing

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1. Suction.
2. Discharge.
3. Packing.
4. Stuffing Box.
5. Glandnuts.
6. Gland Follower.
7. Impeller.

Figure 12-1 Typical back pull - out pump with packing

Likewise, modern braided packing can resist the temperatures
chemicals, shaft velocities, pressures, and operational conditions that are
found in today’s industry.

Corn pressi on pac ki ng

Compression packing is frequently called soft packing because of the
materials of construction used, cut to the proper length to form
packing rings. These rings are packed into the stuffing box around the
shaft. Through the stuffing box and the gland follower, the packing is
compressed to accommodate the interior bore of the stuffing box and
the shaft surface, sealing the pumped liquid.
In the case of valve stems where there is little or no shaft movement,
the packing can be tightened and compressed to seal without any
leakage. In the case of rapid rotational movement, as with the shafts of
centrifugal pumps, or cycling movement in the case of reciprocating
rods, the packing should experience some leakage for lubrication and
cooling.
Packing comes in many forms, sizes, and materials of construction in
order to meet all the needs of industry. And there are specific styles of
packings to satisfy specific needs. The most common fibers used in the
construction of packings include: Asbestos, Linen, Ramey, Jute,
Cotton, Paper, Wool, Hair, Nylon, Rayon, Teflon, Fiberglass, Carbon

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