Centrifugal pumps are the most common type of pumps found in DOE facilities.
Centrifugal pumps enjoy widespread application partly due to their ability to
operate over a wide range of flow rates and pump heads.
STATE the purposes of the following centrifugal pump
Given a drawing of a centrifugal pump, IDENTIFY the
following major components:
Stuffing box gland
Impeller wearing ring
Pump casing wearing ring
Centrifugal pumps basically consist of a stationary pump casing and an impeller mounted on a
rotating shaft. The pump casing provides a pressure boundary for the pump and contains
channels to properly direct the suction and discharge flow. The pump casing has suction and
discharge penetrations for the main flow path of the pump and normally has small drain and vent
fittings to remove gases trapped in the pump casing or to drain the pump casing for maintenance.
Figure 1 is a simplified diagram of a typical centrifugal pump that shows the relative locations
of the pump suction, impeller, volute, and discharge. The pump casing guides the liquid from
the suction connection to the center, or eye, of the impeller. The vanes of the rotating impeller
impart a radial and rotary motion to the liquid, forcing it to the outer periphery of the pump
casing where it is collected in the outer part of the pump casing called the volute. The volute
is a region that expands in cross-sectional area as it wraps around the pump casing. The purpose
of the volute is to collect the liquid discharged from the periphery of the impeller at high
velocity and gradually cause a reduction in fluid velocity by increasing the flow area. This
converts the velocity head to static pressure. The fluid is then discharged from the pump
through the discharge connection.