The flammability envelopes for R-22 in air and enriched air up to 100% O₂ have been measured up to 200 psia (1380 kPa) and ambient temperature. Flammability limits were established from heat of reaction measurements in a bomb calorimeter. The lowest pressure at which R-22 was flammable in air was approxlmately 75 psia (518 kPa). Relatively wide limits were established 100% 0₂ at even 14.7 psia (101 kPa). (Generally, somewhat wider limits may be established in larger vessels.) Measured heats of reaction revealed that regardless of the 0₂/N₂ mixture, flammable compositions between about 30% and 45% R-22 provlded peak heats of reactlon. The flammability envelopes were able to predict the outcome of R-22 flammability tests of other investigators who used slmilar apparatus but fewer values of the 0₂/N₂ ratio.

Units: Dual