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Effect of Suppressants on Metal Fires.


pdf icon Effect of Suppressants on Metal Fires. (1745 K)
Ohlemiller, T. J.; Shields, J. R.

NISTIR 5710; NIST SP 890; Volume 1; 26 p. August 1995.

Fire Suppression System Performance of Alternative Agents in Aircraft Engine and Dry Bay Laboratory Simulations. NIST SP 890. Volume 1, Gann, R. G., Editor, 97-119 pp, November 1995, 1995.

Available from:

Government Printing Office
Order number: SN003-003-03371-5

Keywords:

metal fires; halons; halon alternatives; magnesium; suppression; titanium

Abstract:

As part of a study to determine the impact of halon-alternative fire suppression agents on metal fires, small diameter rods (ca. 1-2 mm) of magnesium and titanium were burned in oxidizing atmospheres containing various percentages of agent vapor. Magnesium was burned in flowing air at pressures of 0.27 and 0.79 MPa (25 and 100 psig). Add-on levels of 5% and, in some cases 10%, by weight of halon 1301, HFC-125, HFC-227ea, FC-218 and CF3I were examined. In all cases, the burning, which had been vigorously established before agent vapor introduction, was extinguished. Titanium was burned in a flowing oxidizing gas containing 40 to 50% oxygen in nitrogen at pressures from 0.31 to 0.79 MPa (30 to 100 psig). Here only halon 1301, HFC-125 and HFC-226ea were added on, at 10% and 15% by weight. All three of these agents slowed, or, in certain cases extinguished, the burning process. Very limited data showed HFC-227ea to slow the burning rate less than did an equal add-on of HFC-125 or halon 1301. The suppressive impact of the agent vapors seen in this study is counter to that in previous studies where burning enhancement has been seen.