NETZSCH NM038BY - 7.4 Shaft Sealing through Single Mechanical Seal

7 MAINTENANCE
PAGE
7.3
7.4 Shaft Sealing through Single Mechanical Seal
There are various constructions of mechanical seals. Especially advantageous is the use
of standard mechanical seals according to DIN 24960. These seals have regardless of
their brand the same fitting dimensions which makes them interchangeable.
Mechanical seals with a coil spring can only be used for pumps which are run in one
direction of rotation.
L The seal specification of a NEMO
®
pump is recorded on the order confirmation sheet.
L Pumps fitted with direction dependent seals should never be run in the opposite
direction of the rotation arrow.
L If excessive leakages occur the spring tension and the seal surfaces should be checked,
and the seal be replaced, if necessary.
Single mechanical seals usually work without any additional equipment. Their
application range can be increased by operating them with a rinsing or cooling
system.
a) Rinsing, especially outside rinsing in accordance with ISO 5199, appendix E,
classification no. 08a or according to API 610, appendix D, plan 32.
Especially with media which are polluted by solids.
A clear rinse (1) is fed in near the area of the
sliding surface. An additional throttle seal (2) can
be built in. This keeps the contaminated medium
(3) away from the seals (4) if:
- sufficient rinse (1) is added
- the pressure of the rinse (1) is greater than the
pressure of the medium (3).
b) Quench, in accordance with ISO 5199,
Appendix E, Plan Nos. 08, 09, 10 or 13 or API
610, Appendix D, Plan No. 62.
Quench is the designation commonly used in sealing engineering for an arrangement
that applies a non pressurized external fluid to the atmospheric side of a mechanical
seal. The quench is used when
- a single mechanical seal will not work or only to a limited extent without auxiliary
measures or
- a double mechanical seal with pressurized buffer fluid is not necessary.
issued: 09.01.2013 Revision: 6
text no.
07400-1/2
copy to:
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IPP - EN - EN_07400_20130109/1 - D8411276 - 4300003998 - 000100 - NPS - 00229929 N 2018-02-21 19:03:25
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