Recall my photos from earlier in this thread. Liquid feed 100% propane, GS-100 stove, no flaring.
Liquid feed, some mix of propane and isobtane (starting mix was 85/15, but canister was 2/3 empty), MicroRocket stove, flaring.
There has been some discussion as to why there was flaring with the one but not the other.
I went out for a brief hike this afternoon. I took along 100% propane again, but this time I took along a Markill HotRod stove (looks very much like a Kovea SupaLite or SnowPeak LiteMax). No flaring.
Guys, it's the fuel. The 100% propane has such a low boiling point that it vaporizes at the drop of a hat. Recall also that the surface area to mass matters. A small tube like the fuel line that connects one end of a Brunton Stove stand to the other has quite a bit of surface area compared to the amount of fuel flowing down the line. Given the length of the line, there's plenty of time for liquid propane to warm up enough to vaporize. Today, it was nice weather here. Probably 50F/10C when I was testing, maybe slightly warmer. All the heat in the world if you're propane and are willing to boil below -40 on either scale.
I did feel the canister, the fuel line, and the adapter I was using. The fuel line and adapter were quite cold. The canister was cold, but not as cold as I would have expected had vapor feed been occurring. The canister by the way was propped up by rocks. I am certain that liquid feed was occurring.
Again, I believe the lack of flaring is due to the use of 100% propane in relatively warm weather. In colder weather, I believe heat would have to be conducted from the burner to the fuel for proper vaporization. How cold would that be with 100% propane? I'm not sure. Perhaps Stuart, David, or Roger would have an insight here.
Adventures In Stoving