Page 150 - Know and Understand Centrifugal Pumps
P. 150
Shaft Deflection
with high velocity there IS
a low pressure zone in
the E-F-G-H- are of the
P = Low pressure
V = High velocity
Figure 9-8
Depending on the pumps available in your manufacturing or process
plant, you will experience:
Broken Shafts.
rn Premature Bearing Failure.
Premature Mechanical Seal Failure.
Premature Packing Failure.
rn Worn and Damaged Shaft Sleeves.
High Maintenance Costs on your Pumps.
You can’t begin to resolve problems in your centrihgal pumps,
bearings and mechanical seals, until you learn the numbers 60°, and
240°, with respect to your pump cutwater.
Operation, design and maintenance
~ ~~~ ~ ~~~
Once again, when the pump is operating at its BEP, all forces within the
volute (velocity, pressure, and the area exposed to velocity and pressure)
are in equilibrium and harmony. The only load on the bearings is the
weight of the shaft. The pump, the mechanical seal, and the bearings
will run for years without problems. When problems arise that cause
high maintenance costs with the pump (remember that seals and
bearings are the principal reason that pumps go into the shop) these
problems normally originate from one of three sources:
