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Stuffing Box Sealing

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Figure 6.5 Multiple springs seal (Reproduced with permission of AESSEAL plc)

Many seals of an earlier design (as was shown in Figure 6.3) use a large
single spring that wraps around the shaft and provides a very strong
closing force to the seal faces during the startup of the pump. The
installation of the single spring is dependent on the rotation of the shaft
to tighten the coil.
The later seal designs opted for a series of smaller springs located
around the shaft to provide a more even loading to the seal faces.
As the smaller springs can clog more readily, many seals of this type are
designed in such a way that the springs are located out of the pumped
fluid entirely.
The most popular design for many aggressive applications is the Metal
Bellows Seal which is made from a series of thin metal discs welded
together to form a leak fight bellows.

Figure 6.6: Metal bellows seal (Reproduced with permission of A. W. Chesterton Inc.)

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