Assessing the clean agent heptafluoropropane by the CUP burner test

Heptafluoropropane is one of the clean agents substituted for Halon for use in gas protection systems. The design concentration with respect to a particular fuel is an important parameter in the system design and will be studied in this article. Current standard requirements for the protection of Class B fires with the clean agent are briefly reviewed. The minimum design concentration will be measured by the cup burner test. Agents were tested on extinguishing fires from three liquid fuels - propanol, petrol, and kerosene. Two different sizes of cups and chimneys are used. The results on heptafluoropropane are compared with two other gaseous extinguishing agents - carbon dioxide and Inergen. This study confirms that the required amount of heptafluoropropane for extinguishing the above three fires is much smaller than the other two agents tested.