Alstom FKG1X - SF6 Use and Handling

GRID
High Voltage Switchgear
PS 0004EN
03
G
.
BE
RNARD
1998-08-12
J
.
VIAT
2011-03-21
1 /
3
S
hee
t
N°
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evision
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rit
ten
by
Date
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igna
tu
re
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proved
by
Date
S
igna
tur
e
Page
SA
FET
Y SHEET
S
F
6
Use and Handling
C
AUS
E
O
R O
R
IG
IN
O
F
HAZ
ARD
.
Sulphur hexafluoride (SF
6
) is
a
ga
s
whic
h in its
ba
s
ic
s
ta
te is
c
olo
url
ess
, od
o
url
ess
a
nd ta
s
tele
s
s
. It i
s
not to
x
ic,
but it c
a
nnot sus
tain life. It i
s
a
hea
vy ga
s
that is dis
pe
r
s
ed
s
lowly int
o the
a
tmos
phe
r
e.
In its natural state, SF
6
is delivered and stored in pressurized tanks (bottles or spheres) at a pressure
of a
pp
r
oxim
a
tely 2
0 ba
r at 20
°C
(in it
s
li
quid
form) and
c
omp
li
es with I
EC
s
tand
a
r
d
37
6.
However, under the effect of the electric arc, the SF
6
molecules break up and the elements mostly
recombine during cooling either due to extinction of the arc or by regeneration caused by the
pres
enc
e o
f a
c
ti
ve a
bsor
be
nt c
harges wi
thi
n the c
ir
c
uit br
ea
ker
.
Various chemical reactions, associated with the volatilization of the materials in contact with the
electric arc, create either fluoridized or sulphurous secondary gas products or solid products in the
form of metallic fluoride powder ; or again, in the presence of traces of water or moisture,
hydrofluoric acid or sulphur dioxide.
In the li
fe-c
ycle o
f the e
quipment, S
F
6
 can be observed not only in its pure state, but also in its
contaminated state :
-
the
us
e
of
new S
F
6
for filling or adding,
-
lea
ks
unde
r
normal
op
erating
c
ond
iti
ons,
-
maintenanc
e inv
olvi
ng the ope
nin
g of c
ir
c
uit
breaker
s
c
onta
ini
ng old S
F
6
 (decomposition
products),
-
ab
norm
a
l
c
ond
it
ions
(i
nter
nal arc fault
c
ausi
ng the s
hiel
ding to br
ea
k)
,
-
c
ir
c
uit
breaker
r
ec
ycling
on end of
li
fe-c
ycle.
WORK REQ
UIREMENT
S.
Follow the
ins
tr
uc
tions
for the tr
a
ns
po
rt
o
f press
uri
zed c
on
ta
iners
.
T
he
s
tor
ag
e
of thes
e
c
ontainer
s
is
gover
ned
by the same s
tor
ag
e
r
egulati
ons as
c
ompr
es
s
ed
ga
s
bo
ttl
es :
-
k
ee
p awa
y
fr
om any
s
ource of heat and in
a c
oo
l,
dry
a
nd well
-venti
lated a
r
ea
,
-
always fit a pressure reducing valve.