John Crane AURA 120NS Installation, Operation & Maintenance Instructions Manual

AURA™ 120NS
GAS SEAL
Foreword
This manual relates to matters affecting the operation of the AURA™
120NS dry gas seals within compressor machinery. It covers areas directly
associated with the installation, removal, operation and maintenance of
the gas seal. For other related subjects, such as the correct operation
of associated systems or guidance when conducting hazard analysis (as
may be required under the European ATEX Directives), consult with the
compressor equipment supplier and their documentation.
The gas seals are robust in operation. However, any incorrect handling or
assembly fitting can easily lead to seal damage. Therefore, John Crane
AURA™ gas seals may only be installed, commissioned and maintained
by a fully trained and authorized plant machinery specialist. This person
must pay close attention to these instructions, the John Crane gas seal
installation drawing, compressor equipment supplier's manuals and
documentation and all relevant regulations. Failure to do this relieves
the manufacturer John Crane from any liability or warranties. It is
strongly recommended that the seals are fitted by John Crane trained and
approved technicians.
Most often, a further seal type is situated between the gas seal and the
compressor bearing chamber. The function of this seal is to prevent the
ingress of bearing oil into the gas seal. This type of seal could be a labyrinth
or some form of mechanical seal and can be known by several generic
names such as tertiary seal, barrier seal or separation seal. Throughout this
document, this seal will be referred to as the separation seal.
If there are any gas seal problems that need an urgent response, please
contact your local John Crane sales representative.
Safety Instructions
The safety notes refer to the gas seal arrangement supplied. They can
never be exclusive and must be used in conjunction with the relevant
safety regulations for the machine, auxiliary equipment, plant and
sealed fluid.
WARNING SYMBOLS
The following symbols are used in this instruction manual to highlight
information of particular importance:
Danger - Mandatory instructions designed to prevent
injury or extensive damage
ATTENTION
Special instructions and/or information to avoid damage
to the seal and/or its surroundings
NOTE Information for easy installation and efficient operation.
Prior to any installation, removal, operation and
maintenance of the gas seals, all personnel involved
in these activities must have read and understood this
document before the commencement of any work. If
there is not adequate understanding, contact John Crane
for further advice.
Installation, Operation & Maintenance Instructions
All personnel involved in the installation, operation
and maintenance of the gas seals must have adequate
training and understanding with regards to:
• The gas seals being used
• The equipment being worked on, including any
relevant auxiliary equipment and systems
• All tooling and equipment associated with fitting and
removing gas seals
• The environment in which work is being carried out
• Health, safety and environmental issues associated
with the above points including all relevant local
site, national and international health, safety and
environmental procedures and regulations.
Any working practice that compromises safety must
be avoided.
All personnel involved in the installation, removal,
operation and maintenance of the gas seals must be
authorized by the responsible party to work on the
equipment that the gas seals are fitted to.
At all times, adequate personal protection equipment
should be worn/used. This equipment needs to be
suitable for the environment and surroundings that a
person is working within.
At all stages in work relating to the gas seal, reference
must be made to the John Crane installation drawing,
this document and the compressor equipment supplier's
manuals and documentation and all relevant regulations.
Gas seal cartridge disassembly is not required for
normal operation and maintenance and must never
be undertaken other than by a John Crane trained
technician approved for the seal type being worked on.
Where gas seals require inspection and refurbishment,
please contact John Crane.
Modifications and/or alterations of the gas seal in any way
are not permitted without the authority of John Crane.
Failure to obtain this authority relieves the manufacturer
John Crane from any liabilities or warranties.
In the event of an operating problem, the machinery
must be immediately switched off and made safe.
Problems must be solved promptly.
A small controlled gas flow (commonly called the gas
seal leakage) will occur within the gas seal during
normal seal operation. In cases of a worn or defective
seals, the leakage volumes will increase. This leakage
may be hazardous, toxic and or explosive.
Attention is also drawn to the fact that, on its own, gas
seal leakage may not be dangerous. However, if it was
to combine with other gases, liquids and/or substances
with increased or decreased pressure and temperature or
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