Here are some pictures to illustrate my point (I apologize for the blurr - I didn't use a tripod and the torch is hand held). The photos on the left are all of the same flame at different regulator settings (5/2, 50/20. and 30/15). This required the valves on the torch to be set at different positions. I did not get any hissing for that small flame at the 50/20 setting . The one photo on the right shows the maximum flame at 50/20.