Temperature classification

The temperature classification of a given gas is the temperature above which an appropriate mixture of that gas with air will ignite. It is critical that the maximum surface temperature of any part of the equipment which may come into contact with the gas/air mixture, does not exceed the ignition temperature of the mixture.

 

The temperature class ‘T rating’ is normally based on an upper ambient temperature of +40 °C

Class T Rating.

Surface Temperature °C Max permittedIgnition Temperature °C Gas/Air mixture
T1450>450
T2 300>300
T3200>200
T4135>135
T5100>100
T685>85