Centrifugal pumps are used to transfer incompressible liquids in different industrial applications. These machines convert the rotational energy (mechanical power) into pressure energy to pump the fluids.
The engine or electric motor generally supplies the mechanical power. Moreover, centrifugal force is used for pumping fluids from low to high-pressure regions. This guide will further discuss the mechanical seals installed in these pumps.
Balanced and Unbalanced Seals
A balanced mechanical seal arrangement is a system in which the forces applying to the face of mechanical seals are balanced. Minimal low face loading means longer seal life and even lubrication of mechanical seal faces.
Balanced mechanical seals are designed for higher operating pressures and can handle liquids with higher volatility and low lubricity.
Unbalanced mechanical seals are more economical and present less product leakage because of the face film’s tighter control. However, this can lead to a reduced mean time between failures. These seals are not recommended to use in high-pressure or hydrocarbon applications.
Cartridge Type Seals
This sealing solution incorporates all seal elements into one assembly, dramatically reducing the risk of assembly error and the time taken for seal replacements. Cartridge seal is enclosed in a sealing system and consists of a sleeve, gland, and other hardware, allowing preassembly. One of the cartridge seal faces rotates with the pump shaft while the other remains stationary.
Pusher and Non-Pusher Seals
Pusher seals are equipped with one or more springs that help maintain the seal closing forces. These springs are either in the stationary or rotating element of the sealing solution. The pusher type provides sealing at extremely high pressures, but the elastomer under the primary seal face is prone to wear.
On the other hand, non-pusher seals feature metal or elastomeric bellows for maintaining seal closing forces. They’re more suitable for high-temperature applications. Pusher and non-pusher seal designs can be found in balanced and unbalanced configurations.
Robco of America manufactures a complete line of cartridges, assembly-style mechanical seals for centrifugal pumps, compressors, mixers, reactors, agitators, and bead mill units.
Our team can also repair all makes and models of mechanical seals used on centrifugal pumps. Choose our custom-designed seals to increase run cycles for a specific industrial application
For reliable mechanical seal repair services, call 1-800-662-0585 for technical support or email us at sales@robcoamerica.com. To learn more, check out our website.
