Oxford-100-Manual.pdf - 第235页
System Manual Oxford Instruments Plasma Technology OIPT Systems 8. Extraction The following mandatory requirements describe the extraction systems recommended by OIPT. While these recommendations may be regarded as "…
OIPT
Systems
Oxford
Instruments
Plasma
Technology
System Manual
7.
Liquid
Nitrogen
WARNING
IF LIQUID NITROGEN FACILITIES ARE NOT INSTALLED, OPERATED
AND
MAINTAINED
CORRECTLY, DANGEROUS SITUATIONS
CAN
RESULT.
THESE
INTRODUCE RISKS
OF:
A)
HAZARDOUS
PRESSURE
BUILD-UP CAUSED
BY
THE
BOIL·OFF
OF
LIQUID
NITROGEN, WHICH
CAN
RESULT
IN
AN
EXPLOSION.
B) PERSONAL INJURY FROM TOUCHING PIPEWORK
OR
OTHER SYSTEM
COMPONENTS CARRYING LIQUID NITROGEN. THIS RISK
CAN
REMAIN
EVEN
AFTER VENTING
THE
CHAMBER.
C)
ASPHYXIATION CAUSED BY
THE
BOILED-OFF LIQUID NITROGEN REPLACING
OXYGEN IN
THE
SYSTEM ENVIRONMENT.
7.1
Mandatory
Requirements
for
Liquid
Nitrogen
systems
•
Ensure
that
the
Liquid
Nitrogen
installation
is
carried
out
in
accordance
with
local
safety
regUlations.
This
includes
the
following:
(a)
No
part
of
the
Liquid
Nitrogen
circuit
can
become
blocked
with
ice
or
other
contaminants.
(b)
Adequate
precautions,
e.g.
pressure
relief
valves,
are
fitted
to
prevent
hazardous
pressure
build-up
from
boil-off
of
the
Liquid
Nitrogen.
(c)
All
system
components
carrying
liqUid
Nitrogen
are
adequately
insulated,
and
covered
to
prevent
personnel
touching
exposed
components.
•
Ensure
that
the
installation
is
inspected
by
a
Specialist
to
confirm
that
it
is
safe
to
use.
Inspections
must
be
carried
out
before
the
system
is
commissioned
and
at
regular
intervals
throughout
its
life.
•
Pipework
from
the
Dewar
to
the
system
must
be
adequately
insulated
and
connected
to
the
system
via
a
3/
8
"
SwaQelok
connector.
Issue
16:
April
05
Services Specifications
Page 16
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System
Manual
Oxford
Instruments
Plasma
Technology
OIPT
Systems
8. Extraction
The
following
mandatory
requirements
describe
the
extraction
systems
recommended
by
OIPT.
While
these
recommendations
may
be
regarded
as
"good
practice",
they
are
not
a
complete
definition
of
the
safety
standards
required
when
handling
toxic,
corrosive
or
otherwise
hazardous
gases.
It
is
the
customer's
responsibility
to
ensure
that
the
installation
meets
all
relevant
local
safety
regulations
and
OIPT
accepts
no
responsibility
in
this
respect.
For
detailed
information
about
the
safety
aspects
of
gas
handling
and
pumping
systems,
the
customer
should
consult
the
relevant
manufacturer/supplier
of
the
gases
and
pumps
to
be
used.
8.1
Mandatory
requirements
for
Rotary
Pump
extraction
The
installation
must
provide
a
rotary
pump
exhaust
extraction
system
which
matches
the
rotary
pump
exhaust
and
which
conforms
to
local
safety
standards.
In
particular,
all
fittings
and
pipework
connected
to
the
rotary
pump
exhaust
must
be
made
from
industry
standard
stainless
steel
in
accordance
with
local
safety
regulations.
Specialised
equipment
such
as
scrubbers
and
furnaces
may
be
needed
to
dispose
of
hazardous
gases.
The
routing
of
the
pump
exhaust
line
must
be
arranged
so
that
condensates
cannot
flow
back
into
the
pump.
Note
that
there
is
a
risk
of
damage
from
cross-contamination
if
rotary
pumps
share
one
exhaust
system.
This
applies
whether
the
pumps
are
on
the
same
system
or
on
different
systems.
Damage
caused
by
any
cross-contamination
is
not
covered
by
the
system
warranty.
Care
must
be
taken
to
route
mutually
incompatible
exhaust
gases
through
separate
exhaust
ducts.
In
particular,
oxygen
enriched
exhaust
gases
should
not
be
mixed
with
exhausts
from
mineral
oil
pumps,
otherwise,
an
explosion
may
occur.
8.2
Mandatory
requirements
for
Gas
Pod
extraction
The
gas
pod
must
be
connected
to
the
customer's
gas
extraction
system
via
a
100
mm
diameter
pipe
collar
to
provide
cabinet
extraction
with
a
minimum
flow
rate
of
1 m
3
/hour
(6-line
gas
pod)
or
3 m
3
/hour
(12-line
gas
pod),
i.e.
an
extraction
vacuum
of
approximately
500
Pa
relative
to
local
atmospheric
pressure
is
required.
It
is
the
customer's
responsibility
to
ensure
that
the
gas
extraction
system,
including
any
necessary
gas
sensors,
meets
local
safety
regUlations.
Printed: 6-Jan-06, 8:44
Services Specifications
Page
17
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Issue
16: April
05
OIPT
Systems
Oxford
Instruments
Plasma
Technology
System Manual
8.3
Mandatory
requirements
for
Cryogenic
pump
extraction
WARNING
ANY
CRYOGENIC PUMP, WHICH PUMPS HAZARDOUS GASES MUST HAVE, A VENT
PIPE FITTED TO ITS RELIEF
VALVE
TO PREVENT
THE
RELEASE
OF
GAS INTO
THE
CLEAN
ROOM.
THE
PUMPS COLLECT
THE
PROCESS GASES
AND
THE GASEOUS RESIDUES DURING
OPERATION. THESE GASES ARE RELEASED THROUGH THE RELIEF
VALVE
DURING
PUMP REGENERATION OR
IF
ELECTRICAL POWER IS LOST.
If
a
cryogenic
pump
is
used
to
pump
toxic,
corrosive,
or
flammable
gases,
a
written
action
plan
is
required.
This
must
be
prepared
in
consultation
with
OIPT
and
other
competent
bodies.
Specialised
equipment
such
as
scrubbers
and
furnaces
may
be
needed
to
dispose
of
hazardous
gases.
If
the
pumped
gases
contain
more
than
20%
oxygen,
a
vent
pipe
must
be
fitted
to
the
system's
cryo
pump
outlet
connector.
The
vent
pipe
must
be
routed
to
a
safe
place
outside
of
the
clean
room
and
conform
to
local
safety
standards.
If
a
cryogenic
pump
is
used
to
pump
gases
containing
more
than
20%
oxygen,
the
associated
roughing
pump(s)
must
be
lubricated
with
a
PFPE
fluid,
e.g.
Fomblin
or
Krytox.
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16:
April
05
Services Specifications
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