Hazardous area apparatus is classified according to the maximum surface temperature produced under the maximum operating capacity at an ambient temperature of 45°C, or as otherwise specified. The standard classifications are:
This is the lowest temperature at which a gas, vapour or dust will be ignited. If a potentially hazardous explosive gas, vapour or dust is present, the equipment used within the installation must be given an appropriate 'T' classification in order to maintain the integrity. For example, if that potentially hazardous explosive gas is hydrogen, then all equipment used must meet the 'T6' rating. This means that all equipment used must not have a surface temperature of greater than 85°C. Any equipment used that can generate a hotter surface temperature of greater than 85°C must not be used as this will then increase the likelihood of an explosion by igniting the hydrogen in the atmosphere.
A large percentage of offshore applications require a 'T3' rating. The majority of our products are rated 'T4, T5 or T6' so are therefore suitable for 'T3' applications. However, if an application requires a 'T5' rated-product, a 'T4' rated product would not be suitable.