Page 201 - Know and Understand Centrifugal Pumps
P. 201
Know and Understand Centrifugal Pumps
- SEALGLAND
SECONDARY STATIC
"0" RING
STATIONARY
RING
Fiaure 13-3
The mechanical seal
The mechanical seal is a device that forms a barrier between rotary and
stationary parts in the pump. The seal must block leakage at three
points (Figure 134):
Between the faces (rotary and stationary) of the seal.
Between the stationary element and the seal chamber housing of
the pump.
Between the rotary element and the shaft or sleeve of the pump.
These basic components and functions are common to all seals. The
form, style, and design vary depending on the service and the
manufacturer. The basic theory of its function and purpose
nevertheless, remains the same.
The set screw that transmits the torque from the shaft is connected to
the rotary face through the spring. It also provides for the positive and
correct positioning of all rotary parts.
SEALING POINTS I
BETWEEN SEAL
AND HOUSING
BETWEEN SHAFT BETWEEN ROTARY
AND SEAL AND STATIONARY
-
FACES
Fiaure 13-4
184 I