Page 236 - Know and Understand Centrifugal Pumps

Failure Analysis of Mechanical Seals

Figure 14-20 The double or dual mechanical seal

1. Crystallization Some liquids form crystals with heat (think of sugar
and rock candy), and others with cold (think of ice). To control and
prevent crystallization in the seal chamber it is necessary to control
the temperature.

w Suction Bypass
w External Flush
Thermal Jacketed seal chamber
Quench and Drain

Heat Exchanger
DualSeal
2. Liquids that Solidify To deal with liquids that try to solidify (think
of ice, cement, glue and paints) it is necessary to identify the cause
and solution for the solidification:

CAUSE OF SOLIDIFICATION SOLUTION
1. Air (paint, glue) Quench and Drain or the Double Seal

2. Change in Temperature (ice) Control the temperature, either up or down.
See Crystallization.
3. Agitation (merengue) Evacuate the seal chamber, suction bypass.
Vacie la camara del sello con una linea hasta
la

4. Time (cement) Evacuate the seal chamber, suction Bypass.

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