Mechanical seals unbalanced

Stuffing Box with Mechanical Seal. Mechanical seal shall he of the (single inside) (single outside) (double inside) (cartridge) type and (balanced) (unbalanced). 

The single, unbalanced, inside mounted mechanical seal... 

Balance - indicates less heat generated. Heat is the principal enemy of all mechanical seals. There simply is no logical reason for specifying unbalanced seals. 

Most designers recommend double mechanical seals, usually unbalanced. Clear water is the best flushing liquid, because there is a possibility of crystallization from concentrated brine within the gland. Seal water may enter the process through the pump seals, and its quality should be chosen with that in mind. The purity of water required depends on the location of a pump within the process. In a membrane-cell plant, only the best grade of water should be used after the ion-exchange step. 

Another characteristic of mechanical seals is balance. Unbalanced seals have the same shaft diameter for both the rotating and stationary elements, as shown on the left of Figure 21-29. The large area of pressure acting to close the unbalanced seal, shown as arrows at the bottom of the cross-section sketch, results in a large force on the seal faces. A balanced seal can reduce the pressure force acting to close the seal faces, by reducing the area on which the pressure acts, as... 

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