5 Function description
5.5 Shaft seal
For the steel material housing variant all flow directions can be realized through different positioning of
the flange connections.
Fig. 9: Housing variants of flange connection
5.5 Shaft seal
The following types of shaft seals are offered:
o
Mechanical seal standard or hard material
o
Mechanical seal with quench
o
Mechanical seal with throttle ring
o
Radial shaft seal standard or high-temperature
5.5.1
Seal variants inner bearing
Mechanical seal standard/hard material
The lubrication of the mechanical seal
1
inevit-
ably results in a low leak, that as a rule evapor-
ates. However, at low-volatile liquids such as
heavy fuel oil the leak becomes visible. The in-
tegrated leakage vent holes
2
allow draining of
this leakage. The drainage through these holes
has to be kept free. Dry running must be avoided
at all costs, as the seal will overheat and be des-
troyed in a matter of seconds.
1
3
2
2
1
Mechanical seal
2
Leakage vent hole
3
Ball bearing
Mechanical seal with quench
If low-volatile liquids or liquids that tend to
harden when coming into contact with the atmo-
sphere are used, a mechanical seal
1
can also
be used in combination with a radial shaft seal
ring
3
. This allows the sealing chamber to be
connected via the leakage vent holes
2
with a
quench tank so that the side of the mechanical
seal facing away from the liquid will always be
kept under the exclusion of air.
1
4
2
2
3
1
Mechanical seal
2
Leakage vent hole for quench tank
connection
3
Radial shaft seal ring
4
Ball bearing
Mechanical seal with throttle ring
The throttle ring
3
serves as a secondary seal in
connection with a mechanical seal
1
. This lightly
contacting seal is for example used to seal a
steam quench, whereby a certain leakage is
emitted permanently via the throttle ring. Such a
quench system is used for the heating and flush-
ing of single action mechanical seals. The
throttle ring furthermore reduces the leak rate at
a total failure of the mechanical seal.
1
3
4
2
2
1
Mechanical seal
2
Leakage vent hole for quench tank
connection
3
Throttle ring
4
Ball bearing
Operating instructions
OIC 18en-GB Edition 2020-01
13
