The “OLIFlex S.P. Inox” single-wall system can be installed with any type of fuel, under both positive and negative pressure. For stoves and chimneys where very high working temperatures are reached, the system must be classified “G”, that is, it must have passed the soot fire resistance test. In general, single-wall systems must not pass through wooden floors or floors made of combustible materials, even it is covered with an insulating material, if, from the external surface of the insulation there is not a distance of at least 70 mm from the combustible material. Also with double-wall systems the distance from combustible materials must be observed, but in this case, the distance must be indicated by the producer of the chimney system. For single-wall systems without insulation, the distance to be observed is three times the diameter of the conduit (for a 200 mm diameter the distance is therefore 600 mm).