FAR DGV18CH Manuel D'utilisation page 73

If the hob is installed above an oven or if
the proximity of other heating appliances
risks heating and damaging the connection,
it is essential to use a rigid tube to make the
connection.
If a flexible pipe is used (e.g. for butane gas),
the latter must not be installed in a place where
there is a risk of contact with moving parts of
furniture and must not pass through a place
likely to be obstructed.
fig.A
Corrugated
reinforced
flexible hose with
mechanical tips
fig.B
Flexible
hose with
mechanical
tips
ENGLISH
GB-27