Page 231 - Know and Understand Centrifugal Pumps

Know and Understand Centrifugal Pumps

The O-ring - is the most widely available and inexpensive elastomer
seal in the world. Practically all rubber compounds are available in
an O-ring configuration. You can buy them from specialty houses or
from the corner hardware store.
The Cartridge Concept - has every component part of the sealing
system in one unit. They’re easier and faster to install and don’t
require total pump teardown. Most come with additional control
ports and rebuild kits.
For most applications, the balanced, O-ring cartridge seal will
adequately handle every pump, liquid, and condition in a modern
industrial process plant. There are, however, some industrial pumping
applications that will present problems to even the best of mechanical
seals. Should one of these applications cause the seal to give less than
desirable performance, the next step to take in extending the service life
of the seal (and ultimately the pump) is to install some type of
environmental control to protect and isolate the seal components from
the fluid. Let’s consider some difficult sealing applications.

Difficult pumping applications for mechanical seals

Crystallizing Liquids
Solidifying Liquids
Vaporizing Liquids

Film Forming Liquids
High Temperature liquids
Non-lubricating Liquids
Dry-Running the Pump
Dangerous Liquids

Gases and Liquids that Phase to Gas
Slurries (Suspended Solids)
Cryogenic Liquids
High Pressure Liquids
Vacuum Conditions

High Speed Pumps
The following pictures show different arrangements of Environmental
Controls. These Controls expand the operational range of the
mechanical seal, improving the pump service life.