On the drifta web site they show you how to reverse the outlet on a three burner stove in the FAQ section, just not quite sure if the three burner primus is the same. We have the three burner Companion stove that Drifta can supply, and it only just fits without reversing the outlet, the hose is on a pretty tight bend, but not too tight that i'm not happy with it tht way.
Lemo.