Smeg GKCO955 - Manual (Page 13)

Instructions for the installer
32
6.3
Arrangement of burners on hob
BURNERS
1
Auxiliary
2 Semi-rapid
3 Rapid
4 Double crown
6.4
Lubrication of gas taps
After a while, the gas tap may become hard to turn or lock. If this
happens, it has to be cleaned inside and re-greased.
This must be done by a qualified technician.